Give the env var its value box back, and stop labelling the secret

Two separate faults, both reachable from one screenshot of the Global
Environment Variables editor.

The value input was collapsed to a sliver, so a variable looked like it
had lost its value. `inputClass` carries `w-full`, and the `w-2/5` on the
key input did not beat it — class-attribute order is not what resolves
that conflict, stylesheet order is. The key therefore asked for the whole
row, and the value input, whose `flex-1` gives it a basis of 0 and only
the leftover space, got almost nothing. Widths now live on wrapper divs,
where nothing competes with them.

The fingerprint that detects custom-env changes was a plaintext
`KEY=VALUE` join, and it is written as the `triple-c.custom-env-fingerprint`
label. Labels are readable by anything on the host via `docker inspect`,
`docker commit` copies them onto the project's snapshot image, and the
recreation check logs both sides on a mismatch — so an API token set as a
custom variable was published to all three. It is hashed now, exactly as
`triple-c.git-token-hash` already was. Empty stays empty, so "nothing
configured" still reads as an empty label.

Changing the fingerprint format means every project's label mismatches
once: expect a single container recreation per project on next start.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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

@@ -318,8 +318,19 @@ fn is_reserved_env_key(key: &str) -> bool {
         || RESERVED_ENV_EXACT.iter().any(|e| upper == *e)
 }
 
-/// Compute a fingerprint string for the custom environment variables.
-/// Sorted alphabetically so order changes do not cause spurious recreation.
+/// Compute a fingerprint for the custom environment variables.
+///
+/// Sorted alphabetically so order changes do not cause spurious recreation, and
+/// **hashed**, because this value is written as the
+/// `triple-c.custom-env-fingerprint` label. Labels are readable by anything on
+/// the host through `docker inspect`, `docker commit` copies them onto the
+/// project's snapshot image, and `container_needs_recreation` logs both sides on
+/// a mismatch — so a plaintext `KEY=VALUE` join published every custom
+/// variable's *value*, API tokens included, to all three places. Same treatment
+/// as `triple-c.git-token-hash`.
+///
+/// Empty stays empty rather than becoming the hash of the empty string: an empty
+/// label is how every other `triple-c.*` key says "nothing configured".
 fn compute_env_fingerprint(custom_env_vars: &[EnvVar]) -> String {
     let mut parts: Vec<String> = Vec::new();
     for env_var in custom_env_vars {
@@ -330,7 +341,10 @@ fn compute_env_fingerprint(custom_env_vars: &[EnvVar]) -> String {
         parts.push(format!("{}={}", key, env_var.value));
     }
     parts.sort();
-    parts.join(",")
+    if parts.is_empty() {
+        return String::new();
+    }
+    sha256_hex(&parts.join(","))
 }
 
 /// The shared Claude Code OAuth token to inject for this project, paired with
@@ -2473,6 +2487,29 @@ mod tests {
         assert_eq!(fp, "");
     }
 
+    #[test]
+    fn the_custom_env_fingerprint_never_carries_the_value() {
+        // It goes into `triple-c.custom-env-fingerprint`, which `docker inspect`
+        // hands to anything on the host, `docker commit` copies onto the
+        // project's snapshot image, and the recreation check logs on a mismatch.
+        let secret = "33da01c1b320644920c20d6b5e0a1c6b3c3451c2";
+        let fp = compute_env_fingerprint(&[EnvVar {
+            key: "TEA_TOKEN".to_string(),
+            value: secret.to_string(),
+        }]);
+        assert!(!fp.contains(secret), "fingerprint leaked the value: {}", fp);
+        assert!(!fp.contains("TEA_TOKEN"), "fingerprint leaked the key: {}", fp);
+        assert_eq!(fp.len(), 64, "expected a sha256 hex digest, got {:?}", fp);
+
+        // It still has to move when the value does, or a rotated token would
+        // never reach the container.
+        let rotated = compute_env_fingerprint(&[EnvVar {
+            key: "TEA_TOKEN".to_string(),
+            value: "rotated".to_string(),
+        }]);
+        assert_ne!(fp, rotated);
+    }
+
     #[test]
     fn the_deprecated_small_fast_model_var_is_never_emitted() {
         let rendered: Vec<String> = aliases(Some("m"), Some("h"))

app/src/components/projects/EnvVarsEditor.tsx

@@ -43,8 +43,15 @@ export default function EnvVarsEditor({
         </p>
       )}
 
+      {/* The row's widths live on wrapper divs, not on the inputs. `inputClass`
+          carries `w-full`, and a width utility on the input itself does not beat
+          it — class-attribute order is not what resolves the conflict, stylesheet
+          order is. Sizing the key input directly left it asking for the whole row
+          and collapsed the value input, whose `flex-1` basis of 0 gave it only the
+          leftover space, to an unusable sliver. */}
       {vars.map((ev, i) => (
         <div key={i} className="flex gap-2 items-center">
+          <div className="w-2/5 shrink-0">
             <input
               value={ev.key}
               onChange={(e) => updateVar(i, "key", e.target.value)}
@@ -52,8 +59,10 @@ export default function EnvVarsEditor({
               placeholder="KEY"
               aria-label={`Environment variable ${i + 1} name`}
               disabled={disabled}
-            className={`w-2/5 ${monoInputClass}`}
+              className={monoInputClass}
             />
+          </div>
+          <div className="flex-1 min-w-0">
             <input
               value={ev.value}
               onChange={(e) => updateVar(i, "value", e.target.value)}
@@ -61,8 +70,9 @@ export default function EnvVarsEditor({
               placeholder="value"
               aria-label={`Environment variable ${i + 1} value`}
               disabled={disabled}
-            className={`flex-1 ${monoInputClass}`}
+              className={monoInputClass}
             />
+          </div>
           <Button
             variant="danger"
             disabled={disabled}