app/src-tauri/src/commands/migration_commands.rs

@@ -461,7 +461,17 @@ async fn fresh_migration(
     // pre-swap commit is the single largest snapshot Triple-C ever takes, so
     // letting this one path commit unscrubbed is what the scrub exists to
     // prevent. Failure is swallowed inside; it must never block a migration.
-    docker::scrub_writable_layer(&container_id).await;
+    //
+    // The outcome is logged rather than discarded: this is the one scrub whose
+    // silence would be expensive, because the layer it declined to clean is
+    // about to be committed into a snapshot that outlives the migration.
+    log::info!(
+        "Pre-migration scrub of {}{}",
+        container_id,
+        docker::scrub_writable_layer(&container_id)
+            .await
+            .commit_log_suffix()
+    );
 
     emit_progress(&app_handle, &project_id, "Stopping the container...");
     let _ = state

app/src-tauri/src/docker/container.rs

@@ -2371,6 +2371,10 @@ const SCRUB_TIMEOUT: std::time::Duration = std::time::Duration::from_secs(120);
 /// The distinction that earns this type is [`ScrubOutcome::NotRunning`] versus
 /// [`ScrubOutcome::Failed`]: "there was nothing to exec into" is routine, while
 /// "the exec ran and broke" is the one case worth a warning in the log.
+/// `#[must_use]` because the variants mean different things to a caller and
+/// three of the four are easy to ignore by accident: a `Failed` swallowed at a
+/// call site is exactly how a scrub that stopped working would stay quiet.
+#[must_use = "a scrub that was skipped, timed out or failed reads the same as one that worked unless the outcome is inspected"]
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum ScrubOutcome {
     /// The scrub ran to completion and freed this many bytes — possibly zero,
@@ -2397,7 +2401,7 @@ impl ScrubOutcome {
     /// nothing to exec into. A figure of zero reads as a scrub that ran and
     /// found nothing, which is a different and more alarming thing than a
     /// scrub that correctly had no work left.
-    fn commit_log_suffix(&self) -> String {
+    pub(crate) fn commit_log_suffix(&self) -> String {
         match self {
             Self::Reclaimed(bytes) => format!(
                 " ({:.2} MB dropped by the pre-commit scrub)",

app/src-tauri/src/lib.rs

@@ -727,4 +727,68 @@ mod tests {
         lifecycle.settle_startup_tasks().await;
         assert!(started.elapsed() <= STARTUP_CANCEL_BUDGET + Duration::from_secs(1));
     }
+
+    /// The capability file is the app's entire IPC attack surface, and it is
+    /// data — nothing in `cargo test` reads it, so a widened grant lands with a
+    /// green suite. This is what noticing looks like.
+    ///
+    /// It exists because `core:default` was granted for months. That alias
+    /// pulls in `core:image:default` → `allow-from-path`, which is an
+    /// unconditional `std::fs::read` of any host path with no scope check, and
+    /// nothing in the frontend has ever imported `@tauri-apps/api/image`.
+    #[test]
+    fn the_capability_grants_are_the_ones_that_were_reviewed() {
+        let raw = include_str!("../capabilities/default.json");
+        let parsed: serde_json::Value =
+            serde_json::from_str(raw).expect("capabilities/default.json must parse");
+        let listed: Vec<String> = parsed["permissions"]
+            .as_array()
+            .expect("a `permissions` array")
+            .iter()
+            .map(|p| match p {
+                // A scoped grant is an object; its identifier is what matters here.
+                serde_json::Value::Object(o) => o["identifier"]
+                    .as_str()
+                    .expect("a scoped grant needs an identifier")
+                    .to_string(),
+                other => other.as_str().expect("a grant is a string or an object").to_string(),
+            })
+            .collect();
+
+        let mut sorted = listed.clone();
+        sorted.sort();
+        let mut expected = vec![
+            "core:event:allow-listen",
+            "core:event:allow-unlisten",
+            "core:webview:allow-internal-toggle-devtools",
+            "dialog:allow-open",
+            "dialog:allow-save",
+            "opener:allow-open-url",
+            "drag:allow-start-drag",
+        ];
+        expected.sort();
+        assert_eq!(
+            sorted, expected,
+            "the capability set changed. That is allowed — but it is the IPC \
+             surface a compromised webview can call, so update this list \
+             deliberately rather than to make the test pass."
+        );
+
+        // Belt and braces: the `*:default` aliases are the specific trap here,
+        // because they expand to a set the file never spells out. `store:*` in
+        // particular was an arbitrary host-file read/write primitive.
+        for grant in &listed {
+            assert!(
+                !grant.ends_with(":default"),
+                "{} is an alias — it expands to permissions this file does not \
+                 name. Enumerate them instead.",
+                grant
+            );
+            assert!(
+                !grant.starts_with("store:"),
+                "store:* is `PathBuf::push` against AppData, which an absolute \
+                 path discards: an arbitrary host-file read/write."
+            );
+        }
+    }
 }

app/src-tauri/src/project_lock.rs

@@ -151,6 +151,10 @@ fn holders() -> &'static Mutex<HashMap<String, ProjectOp>> {
 /// predecessor already learned: a plain release statement is skipped by an
 /// early `?`, by a panic, and by the future simply being dropped. A guard is
 /// not.
+/// Dropping this releases the claim, so a caller that discards it has taken no
+/// lock at all — `let _ = try_acquire(...)` drops immediately and reads as
+/// success. `#[must_use]` makes that a compile warning rather than a race.
+#[must_use = "the claim is released as soon as this guard is dropped; bind it for the whole operation"]
 #[derive(Debug)]
 pub struct ProjectGuard {
     project_id: String,
@@ -245,8 +249,11 @@ mod tests {
         assert!(err.contains("snapshot is being compacted"), "{}", err);
         assert!(err.contains("starting or recreating"), "{}", err);
         drop(first);
-        // And it has to be retakeable the moment the holder goes away.
+        // And it has to be retakeable the moment the holder goes away. Bound
-        try_acquire(&p, ProjectOp::Recreate).expect("released on drop");
+        // rather than discarded: `#[must_use]` is what stops a real caller
+        // writing `try_acquire(...)` and believing it holds something.
+        let retaken = try_acquire(&p, ProjectOp::Recreate).expect("released on drop");
+        drop(retaken);
     }
 
     #[test]

app/src/components/projects/home/config/AccessSection.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useState } from "react";
+import { useSecretField } from "../../../../hooks/useSecretField";
 import { open } from "@tauri-apps/plugin-dialog";
 import type { Project } from "../../../../lib/types";
 import Button from "../../../ui/Button";
@@ -24,14 +25,15 @@ export default function AccessSection({
   const [caCertPath, setCaCertPath] = useState(project.ca_cert_path ?? "");
   const [gitName, setGitName] = useState(project.git_user_name ?? "");
   const [gitEmail, setGitEmail] = useState(project.git_user_email ?? "");
-  const [gitToken, setGitToken] = useState(project.git_token ?? "");
+  // Never seeded from `project` — the backend does not serialize secrets, so
+  // the box is always empty and only an edit may speak about the stored value.
+  const gitToken = useSecretField(project.id);
 
   useEffect(() => {
     setSshKeyPath(project.ssh_key_path ?? "");
     setCaCertPath(project.ca_cert_path ?? "");
     setGitName(project.git_user_name ?? "");
     setGitEmail(project.git_user_email ?? "");
-    setGitToken(project.git_token ?? "");
   }, [project]);
 
   return (
@@ -101,15 +103,19 @@ export default function AccessSection({
 
       <Field
         label="Git HTTPS token"
-        hint="A personal access token (e.g. a GitHub PAT) for HTTPS git operations inside the container."
+        hint={
+          gitToken.edited
+            ? "Saved when you click away. Clearing the box removes the stored token."
+            : "A personal access token (e.g. a GitHub PAT) for HTTPS git operations inside the container. A stored token is not shown; leave this empty to keep it."
+        }
       >
         {(id) => (
           <input
             id={id}
             type="password"
-            value={gitToken}
+            value={gitToken.value}
-            onChange={(e) => setGitToken(e.target.value)}
+            onChange={(e) => gitToken.setValue(e.target.value)}
-            onBlur={() => save({ git_token: gitToken || null })}
+            onBlur={() => save({ ...gitToken.patch("git_token") })}
             placeholder="ghp_…"
             disabled={disabled}
             className={inputClass}

app/src/components/projects/home/config/ModelSection.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useState } from "react";
+import { useSecretField, withoutUntouchedSecrets } from "../../../../hooks/useSecretField";
 import type {
   Backend,
   BedrockAuthMethod,
@@ -16,6 +17,17 @@ import Field, {
 } from "../../../ui/Field";
 import Toggle from "../../../ui/Toggle";
 
+/** Bedrock fields held in the OS keychain, never serialized back to us. */
+const BEDROCK_SECRET_KEYS = [
+  "aws_access_key_id",
+  "aws_secret_access_key",
+  "aws_session_token",
+  "aws_bearer_token",
+] as const;
+
+/** The same, for the OpenAI-compatible backend. */
+const OPENAI_SECRET_KEYS = ["api_key"] as const;
+
 export const DEFAULT_BEDROCK_CONFIG: BedrockConfig = {
   auth_method: "static_credentials",
   aws_region: "us-east-1",
@@ -65,11 +77,12 @@ export default function ModelSection({ project, save, disabled }: Props) {
 
   // Local text state — saved on blur, not on every keystroke.
   const [bedrockRegion, setBedrockRegion] = useState(bedrock.aws_region);
-  const [accessKeyId, setAccessKeyId] = useState(bedrock.aws_access_key_id ?? "");
+  // Secrets are never seeded from `project` — see `useSecretField`.
-  const [secretKey, setSecretKey] = useState(bedrock.aws_secret_access_key ?? "");
+  const accessKeyId = useSecretField(project.id);
-  const [sessionToken, setSessionToken] = useState(bedrock.aws_session_token ?? "");
+  const secretKey = useSecretField(project.id);
+  const sessionToken = useSecretField(project.id);
   const [profile, setProfile] = useState(bedrock.aws_profile ?? "");
-  const [bearerToken, setBearerToken] = useState(bedrock.aws_bearer_token ?? "");
+  const bearerToken = useSecretField(project.id);
   const [bedrockModelId, setBedrockModelId] = useState(bedrock.model_id ?? "");
   const [serviceTier, setServiceTier] = useState(bedrock.service_tier ?? "");
 
@@ -97,9 +110,7 @@ export default function ModelSection({ project, save, disabled }: Props) {
     project.openai_compatible_config?.base_url ??
       DEFAULT_OPENAI_COMPATIBLE_CONFIG.base_url,
   );
-  const [oaiApiKey, setOaiApiKey] = useState(
+  const oaiApiKey = useSecretField(project.id);
-    project.openai_compatible_config?.api_key ?? "",
-  );
   const [oaiModelId, setOaiModelId] = useState(
     project.openai_compatible_config?.model_id ?? "",
   );
@@ -107,14 +118,13 @@ export default function ModelSection({ project, save, disabled }: Props) {
     project.openai_compatible_config?.haiku_model_id ?? "",
   );
 
+  // Secret fields are deliberately absent here: `useSecretField` owns its own
+  // reset, and re-seeding one from `project` would write an empty string over
+  // whatever the user had half-typed on any unrelated project update.
   useEffect(() => {
     const bc = project.bedrock_config ?? DEFAULT_BEDROCK_CONFIG;
     setBedrockRegion(bc.aws_region);
-    setAccessKeyId(bc.aws_access_key_id ?? "");
-    setSecretKey(bc.aws_secret_access_key ?? "");
-    setSessionToken(bc.aws_session_token ?? "");
     setProfile(bc.aws_profile ?? "");
-    setBearerToken(bc.aws_bearer_token ?? "");
     setBedrockModelId(bc.model_id ?? "");
     setServiceTier(bc.service_tier ?? "");
     setOllamaBaseUrl(project.ollama_config?.base_url ?? DEFAULT_OLLAMA_CONFIG.base_url);
@@ -129,13 +139,18 @@ export default function ModelSection({ project, save, disabled }: Props) {
       project.openai_compatible_config?.base_url ??
         DEFAULT_OPENAI_COMPATIBLE_CONFIG.base_url,
     );
-    setOaiApiKey(project.openai_compatible_config?.api_key ?? "");
     setOaiModelId(project.openai_compatible_config?.model_id ?? "");
     setOaiHaikuModelId(project.openai_compatible_config?.haiku_model_id ?? "");
   }, [project]);
 
   const saveBedrock = (patch: Partial<BedrockConfig>) =>
-    save({ bedrock_config: { ...bedrock, ...patch } });
+    save({
+      bedrock_config: withoutUntouchedSecrets(
+        { ...bedrock, ...patch },
+        patch,
+        BEDROCK_SECRET_KEYS,
+      ),
+    });
 
   const saveOllama = (patch: Partial<OllamaConfig>) =>
     save({
@@ -152,10 +167,14 @@ export default function ModelSection({ project, save, disabled }: Props) {
 
   const saveOpenAi = (patch: Partial<OpenAiCompatibleConfig>) =>
     save({
-      openai_compatible_config: {
+      openai_compatible_config: withoutUntouchedSecrets(
+        {
           ...(project.openai_compatible_config ?? DEFAULT_OPENAI_COMPATIBLE_CONFIG),
           ...patch,
         },
+        patch,
+        OPENAI_SECRET_KEYS,
+      ),
     });
 
   // Defaults to on: projects created before the field existed, and any data
@@ -261,9 +280,9 @@ export default function ModelSection({ project, save, disabled }: Props) {
                 {(id) => (
                   <input
                     id={id}
-                    value={accessKeyId}
+                    value={accessKeyId.value}
-                    onChange={(e) => setAccessKeyId(e.target.value)}
+                    onChange={(e) => accessKeyId.setValue(e.target.value)}
-                    onBlur={() => saveBedrock({ aws_access_key_id: accessKeyId || null })}
+                    onBlur={() => saveBedrock(accessKeyId.patch("aws_access_key_id"))}
                     placeholder="AKIA…"
                     disabled={disabled}
                     className={monoInputClass}
@@ -278,10 +297,10 @@ export default function ModelSection({ project, save, disabled }: Props) {
                   <input
                     id={id}
                     type="password"
-                    value={secretKey}
+                    value={secretKey.value}
-                    onChange={(e) => setSecretKey(e.target.value)}
+                    onChange={(e) => secretKey.setValue(e.target.value)}
                     onBlur={() =>
-                      saveBedrock({ aws_secret_access_key: secretKey || null })
+                      saveBedrock(secretKey.patch("aws_secret_access_key"))
                     }
                     disabled={disabled}
                     className={monoInputClass}
@@ -296,10 +315,10 @@ export default function ModelSection({ project, save, disabled }: Props) {
                   <input
                     id={id}
                     type="password"
-                    value={sessionToken}
+                    value={sessionToken.value}
-                    onChange={(e) => setSessionToken(e.target.value)}
+                    onChange={(e) => sessionToken.setValue(e.target.value)}
                     onBlur={() =>
-                      saveBedrock({ aws_session_token: sessionToken || null })
+                      saveBedrock(sessionToken.patch("aws_session_token"))
                     }
                     disabled={disabled}
                     className={monoInputClass}
@@ -337,9 +356,9 @@ export default function ModelSection({ project, save, disabled }: Props) {
                 <input
                   id={id}
                   type="password"
-                  value={bearerToken}
+                  value={bearerToken.value}
-                  onChange={(e) => setBearerToken(e.target.value)}
+                  onChange={(e) => bearerToken.setValue(e.target.value)}
-                  onBlur={() => saveBedrock({ aws_bearer_token: bearerToken || null })}
+                  onBlur={() => saveBedrock(bearerToken.patch("aws_bearer_token"))}
                   disabled={disabled}
                   className={monoInputClass}
                 />
@@ -507,9 +526,9 @@ export default function ModelSection({ project, save, disabled }: Props) {
               <input
                 id={id}
                 type="password"
-                value={oaiApiKey}
+                value={oaiApiKey.value}
-                onChange={(e) => setOaiApiKey(e.target.value)}
+                onChange={(e) => oaiApiKey.setValue(e.target.value)}
-                onBlur={() => saveOpenAi({ api_key: oaiApiKey || null })}
+                onBlur={() => saveOpenAi(oaiApiKey.patch("api_key"))}
                 placeholder="sk-…"
                 disabled={disabled}
                 className={monoInputClass}

app/src/components/projects/home/config/WorkspaceSection.tsx

@@ -19,6 +19,22 @@ export default function WorkspaceSection({ project, save, disabled }: Props) {
     setPaths(project.paths ?? []);
   }, [project]);
 
+  /**
+   * Save only when every row is fully filled in.
+   *
+   * Both inputs save on blur, so tabbing from the host path to the mount name
+   * fires a save with the name still empty. `update_project` now validates —
+   * a half-filled row is refused — so the unconditional save turned an ordinary
+   * keystroke into an error toast. A blank row is *not* incomplete: the
+   * "+ Add folder" button adds one deliberately, and it is dropped on save.
+   */
+  const saveIfComplete = () => {
+    const filled = paths.filter((p) => p.host_path.trim() || p.mount_name.trim());
+    const halfFilled = filled.some((p) => !p.host_path.trim() || !p.mount_name.trim());
+    if (halfFilled) return;
+    return save({ paths });
+  };
+
   return (
     <ConfigGroup
       title="Workspace"
@@ -70,7 +86,7 @@ export default function WorkspaceSection({ project, save, disabled }: Props) {
                   updated[i] = { ...updated[i], host_path: e.target.value };
                   setPaths(updated);
                 }}
-                onBlur={() => save({ paths })}
+                onBlur={() => saveIfComplete()}
                 placeholder="/path/to/folder"
                 disabled={disabled}
                 className={`flex-1 min-w-0 ${inputClass}`}
@@ -107,7 +123,7 @@ export default function WorkspaceSection({ project, save, disabled }: Props) {
                     updated[i] = { ...updated[i], mount_name: e.target.value };
                     setPaths(updated);
                   }}
-                  onBlur={() => save({ paths })}
+                  onBlur={() => saveIfComplete()}
                   placeholder="name"
                   disabled={disabled}
                   className={`w-40 ${monoInputClass}`}

app/src/components/settings/SharedAuthSettings.tsx

@@ -46,12 +46,12 @@ const STATUS_DISPLAY: Record<
  * snapshot was never attempted, so the remedy is to run the sweep again, not
  * to Reset the project and lose both its volumes.
  *
- * `snapshots_skipped` is read defensively: it is newer than `ClearTokenOutcome`
+ * `snapshots_skipped` is declared on `ClearTokenOutcome`, but it is still read
- * in `lib/types.ts`, which another change in this round owns. Until that lands
+ * through `list()` rather than indexed directly: a backend older than this
- * the field arrives over IPC but is not in the declared type, and an older
+ * change does not send the field at all, and a missing skip list must read as
- * backend would not send it at all.
+ * "nothing was skipped" rather than crashing the panel that reports it.
  */
-type RevokeOutcome = ClearTokenOutcome & { snapshots_skipped?: string[] };
+type RevokeOutcome = ClearTokenOutcome;
 
 const list = (values: string[] | undefined): string[] => values ?? [];
 

app/src/hooks/useSecretField.test.ts

@@ -0,0 +1,77 @@
+import { describe, it, expect } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+import { useSecretField, withoutUntouchedSecrets } from "./useSecretField";
+
+describe("useSecretField", () => {
+  it("says nothing about a secret the user never touched", () => {
+    // The bug this exists for: the input always renders empty (secrets are
+    // never serialized to the frontend), so the obvious `value || null` blur
+    // handler sent `null` — which means *delete* — merely because the user
+    // focused the field and tabbed away. No warning, nothing to undo.
+    const { result } = renderHook(() => useSecretField("p1"));
+    expect(result.current.value).toBe("");
+    expect(result.current.edited).toBe(false);
+    expect(result.current.patch("git_token")).toEqual({});
+    // Absent, not null: `JSON.stringify` drops the key entirely, and Rust
+    // distinguishes an absent key ("leave it") from an explicit null ("clear").
+    expect("git_token" in result.current.patch("git_token")).toBe(false);
+  });
+
+  it("sends the value once the user types", () => {
+    const { result } = renderHook(() => useSecretField("p1"));
+    act(() => result.current.setValue("ghp_secret"));
+    expect(result.current.patch("git_token")).toEqual({ git_token: "ghp_secret" });
+  });
+
+  it("sends null only when the user cleared a field they had typed in", () => {
+    // This is the one case where deleting the stored secret is what was asked
+    // for, and it has to keep working — the previous behaviour skipped `None`
+    // entirely, so a blanked token was never actually revoked.
+    const { result } = renderHook(() => useSecretField("p1"));
+    act(() => result.current.setValue("typed"));
+    act(() => result.current.setValue(""));
+    expect(result.current.edited).toBe(true);
+    expect(result.current.patch("git_token")).toEqual({ git_token: null });
+  });
+
+  it("forgets a half-typed secret when the editor moves to another project", () => {
+    const { result, rerender } = renderHook(({ id }) => useSecretField(id), {
+      initialProps: { id: "p1" },
+    });
+    act(() => result.current.setValue("for-project-one"));
+    rerender({ id: "p2" });
+    expect(result.current.value).toBe("");
+    expect(result.current.edited).toBe(false);
+    expect(result.current.patch("api_key")).toEqual({});
+  });
+});
+
+describe("withoutUntouchedSecrets", () => {
+  it("drops a secret key the caller did not set", () => {
+    // `saveBedrock` spreads `{ ...bedrock, ...patch }`, and when `bedrock`
+    // falls back to DEFAULT_BEDROCK_CONFIG that literal spells every secret out
+    // as `null`. Without this filter, editing the AWS *region* would delete the
+    // stored credentials as a side effect.
+    const merged = {
+      aws_region: "eu-west-1",
+      aws_access_key_id: null,
+      aws_secret_access_key: null,
+    };
+    const out = withoutUntouchedSecrets(merged, { aws_region: "eu-west-1" }, [
+      "aws_access_key_id",
+      "aws_secret_access_key",
+    ]);
+    expect(out).toEqual({ aws_region: "eu-west-1" });
+    expect("aws_access_key_id" in out).toBe(false);
+  });
+
+  it("keeps a secret key the caller set, including an explicit null", () => {
+    const merged = { aws_region: "eu-west-1", aws_access_key_id: null };
+    const out = withoutUntouchedSecrets(
+      merged,
+      { aws_access_key_id: null },
+      ["aws_access_key_id"],
+    );
+    expect(out).toEqual({ aws_region: "eu-west-1", aws_access_key_id: null });
+  });
+});

app/src/hooks/useSecretField.ts

@@ -0,0 +1,96 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+
+/**
+ * A password input whose stored value the frontend can never see.
+ *
+ * Secrets live in the OS keychain and are `#[serde(skip_serializing)]`, so a
+ * `Project` arriving from Rust has no key for them at all and the input always
+ * renders empty — whether or not a credential is stored. That is fine on its
+ * own. What is not fine is the obvious blur handler:
+ *
+ * ```tsx
+ * onBlur={() => save({ git_token: gitToken || null })}
+ * ```
+ *
+ * An empty box sends `null`, and `null` now means **delete** (it used to mean
+ * "skip", which was its own bug — a blanked token was never actually revoked).
+ * So merely focusing a secret field and tabbing away destroyed the stored
+ * credential, with nothing shown and nothing to undo it.
+ *
+ * The rule this encodes: **only a field the user actually typed in may speak
+ * about a secret.** `patch()` returns `undefined` until then, and `undefined`
+ * is dropped by `JSON.stringify`, so the key never reaches Rust — which
+ * deliberately distinguishes an absent key ("leave it alone") from an explicit
+ * `null` ("clear it"). See `explicitly_cleared_secrets` in
+ * `commands/project_commands.rs`.
+ */
+export interface SecretField {
+  /** Current input value. Always starts empty for a stored secret. */
+  value: string;
+  /** Whether the user has typed in this field since it was last reset. */
+  edited: boolean;
+  /** `onChange` handler — marks the field edited. */
+  setValue: (next: string) => void;
+  /**
+   * What to put in the save patch, spread into it:
+   * `save({ ...token.patch("git_token") })`.
+   *
+   * Empty when untouched, so the key is absent and the stored secret stands.
+   */
+  patch: <K extends string>(key: K) => Partial<Record<K, string | null>>;
+}
+
+export function useSecretField(projectId: string): SecretField {
+  const [value, setValueRaw] = useState("");
+  const [edited, setEdited] = useState(false);
+  // Reset when the editor moves to a different project, so a value typed for
+  // one project can never be saved onto another.
+  const lastProject = useRef(projectId);
+
+  useEffect(() => {
+    if (lastProject.current !== projectId) {
+      lastProject.current = projectId;
+      setValueRaw("");
+      setEdited(false);
+    }
+  }, [projectId]);
+
+  const setValue = useCallback((next: string) => {
+    setValueRaw(next);
+    setEdited(true);
+  }, []);
+
+  const patch = useCallback(
+    <K extends string>(key: K): Partial<Record<K, string | null>> =>
+      edited ? ({ [key]: value || null } as Partial<Record<K, string | null>>) : {},
+    [edited, value],
+  );
+
+  return { value, edited, setValue, patch };
+}
+
+/**
+ * Drop secret keys the caller did not explicitly set.
+ *
+ * The config editors save by spreading — `save({ bedrock_config: { ...bedrock,
+ * ...patch } })`. That is safe while `bedrock` comes from Rust, because secrets
+ * are never serialized and the keys are simply absent. It stops being safe the
+ * moment the spread falls back to a `DEFAULT_*_CONFIG` literal, because those
+ * spell every secret out as `null` — and `null` means delete. Editing the AWS
+ * region would then wipe the stored credentials as a side effect.
+ *
+ * So the merged object is filtered: a secret key survives only if it is in the
+ * caller's own patch, which is to say only if a `useSecretField` that the user
+ * typed into put it there.
+ */
+export function withoutUntouchedSecrets<T extends object>(
+  merged: T,
+  patch: Partial<T>,
+  secretKeys: readonly (keyof T)[],
+): T {
+  const out = { ...merged };
+  for (const key of secretKeys) {
+    if (!(key in patch)) delete out[key];
+  }
+  return out;
+}

app/src/lib/types.ts

@@ -643,6 +643,12 @@ export interface ClearTokenOutcome {
   snapshots_scrubbed: string[];
   /** Images still holding it, each with the reason. Non-empty = incomplete. */
   snapshots_failed: string[];
+  /** Images left alone because the project was busy under the per-project lock
+   *  (a compaction, a migration, a recreate). **Not a failure and not a
+   *  success** — the token is still baked into these, and `clearClaudeToken`
+   *  is itself the retry. Kept separate from `snapshots_failed` so a skipped
+   *  credential removal can never be reported as a completed one. */
+  snapshots_skipped: string[];
   /** Rewritten, but the pre-rewrite image object could not be deleted because a
    *  container still runs off it. Clears itself when that container is
    *  recreated — worth mentioning, not worth alarming about. */