Stop Docker disk growth, and fix the Claude Code settings that never worked

Two independent sets of fixes.

## Disk: stop the growth, no UI this round

The dangling-snapshot sweep was already correct and was never the leak. The
leak is that every `docker commit` **stacks** a layer and nothing compacts one:
a file deleted after it has been committed becomes a whiteout, not free bytes.
24 conditions trigger recreation+commit, so changing one settings field costs a
multi-gigabyte layer for the life of the project. One project was measured with
14 stacked commit layers, ~5.1 GB above its base.

* **Scrub the writable layer before every commit** (`docker/container.rs`,
  `SNAPSHOT_SCRUB_PATHS` / `scrub_writable_layer`). The one moment those bytes
  are still free to drop is before the commit that captures them. Measured on
  one container's 4.48 GB pending layer: 3.0 GB of agent scratchpad under
  `/tmp/claude-*`, the terminal drag-drop staging area (256 MiB per file, with
  no `rm` for it anywhere in the repo), a PNG per pasted image, and the apt
  lists/cache/logs that `browser_view/install.rs` and `triple-c-playwright-heal`
  leave behind with no `apt-get clean`. A hardcoded list, never a heuristic:
  `/workspace/{mount_name}` is a host bind mount and nothing here may reach one,
  and the three `/tmp` globs cannot select the read-only `.host-ca`/`.host-aws`
  mounts. Failure is a log line — a scrub must never block a snapshot.

* **Cap container logs** (`capped_log_config`). There was no `LogConfig`
  anywhere, so containers ran on the daemon's unbounded `json-file` default.
  Deliberately *not* wired into `container_needs_recreation`: participating
  would recreate every project once, and a recreation costs a commit, which is
  the thing being fixed. Picked up on the next natural recreation.

* **Make superseded base images sweepable** (`container/Dockerfile`). It carried
  no `LABEL` at all, so `orphan_sweep_filters`' `dangling` + `triple-c.managed`
  pair provably could not match one — ~11.9 GB observed stranded. Stamping
  `triple-c.managed=true` is the whole fix; the sweep needed no change.
  `create_container` writes the new `triple-c.base` key explicitly empty, or
  Docker's label inheritance plus `docker commit` would make every snapshot
  claim to be a base image. `force: false` stays, and now says why.

* **Sweep at startup** (`lib.rs`), not only after recreation: probes first
  (a probe pins an image the unforced sweep then refuses), pins second, sweep
  last. `sweep_orphaned_snapshots_logged` exists because all three callers threw
  the report away — `reclaimed_bytes`, `failed` and `unavailable` included.

* **Reap migration leftovers.** `rollback_migration` retagged and orphaned the
  migrated snapshot with no sweep. Stale `pre-migration-*` pins are now
  age-reaped by scanning the tag pattern rather than trusting the state file —
  `migration_store::load` reports an unparseable record as absent, which
  stranded a 4-12 GB pin nothing could name again; `load` now moves a corrupt
  record aside so `has_record` is trustworthy. A pin whose migration is still
  awaiting confirmation is never reaped at any age. The probe container's
  removal was a plain statement after an await, so a dropped future (an app quit
  mid-migration) leaked a container pinning a multi-gigabyte image; it is a
  `Drop` guard now, with `reap_probe_containers` for the case where the process
  itself dies.

* **Prune scheduler logs.** `remove` deleted a task's JSON but never its log
  directory, and the task runner appended uncapped `claude -p` output.

* **Fix the delete copy.** It said "the container, config volume, and stored
  credentials"; it removes *both* volumes and the snapshot image.

No prune UI, and no unfiltered `prune_images`/`prune_volumes` anywhere — the
daemon is shared with the user's unrelated work.

## Claude Code settings: two invented keys, one inverted default, one sticky bug

Verified against code.claude.com/docs/en/settings-reference.md and env-vars.md.

* `effort` -> **`effortLevel`**, the key Claude Code actually reads; the old one
  was written and silently ignored. `xhigh` added to the dropdown.
* `focusMode` -> **`viewMode: "focus"`**. `focusMode` was invented. The real key
  does exactly what the existing UI hint already described.
* **Session recap was inverted.** Claude Code's recap is on by default, so
  `CLAUDE_CODE_ENABLE_AWAY_SUMMARY=1`-when-enabled was a no-op and the control
  could never turn the recap *off*. The field is renamed to
  `session_recap_disabled` rather than reused: reusing the name with the
  opposite meaning would have read every stored `enable_session_recap: false` —
  which is every project that never touched the control — as "the user turned
  this off".
* **The stickiness, which is the important one.** Keys were emitted only when
  non-default, and the entrypoint *merges* into a settings.json on a persisted
  volume, so switching a setting off omitted its key, the merge preserved the
  stale on-value, and the setting stayed on until a destructive Reset. The fix
  already existed in the same file — the sandbox block is emitted
  unconditionally for exactly this reason — and is now applied to all five keys.
  A key whose neutral state is *unset* (`tui`, `effortLevel`, `viewMode`,
  `awaySummaryEnabled`) is emitted as JSON `null` and the entrypoint deletes it,
  because a stand-in value is not neutral: `tui: "default"` pins the classic
  renderer where unset lets Claude Code choose, and `viewMode: "default"`
  overrides the user's own sticky `/focus` choice.
* The same stickiness existed, unnoticed, in the **env vars**: `docker commit`
  bakes container env into the snapshot image, so a `=1` written once rode it
  forever. All four are now emitted on every create, extracted into
  `claude_code_env_vars` and unit tested. Two use an empty value for "off"
  rather than `0`, because they outrank a setting the user can change from
  inside their own container and Triple-C's default must not overrule a
  `/config` choice it never asked about.
* TUI mode is now a genuine three-way choice (automatic / classic / fullscreen),
  which the always-emitted key makes both necessary and possible.

`merge_claude_code_settings` is untouched by choice: a project-level OFF still
cannot override a globally-ON setting.

Tests: 364 frontend (+5), 308 Rust (+23), covering the scrub path list and
script, log rotation, pin reaping, and that toggling a setting off actually
clears a previously-set ON value.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GBq2rGum6GX7xXgsas1fDc

app/src-tauri/src/models/project.rs

@@ -86,24 +86,42 @@ impl PermissionMode {
 /// These map to Claude Code env vars and ~/.claude/settings.json entries.
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default)]
 pub struct ClaudeCodeSettings {
-    /// TUI rendering mode: None = default, Some("fullscreen") = flicker-free alt-screen
+    /// TUI renderer. `None` leaves settings.json's `tui` key unset, which is
+    /// what lets Claude Code pick the renderer itself; `Some("default")` pins
+    /// the classic main-screen renderer and `Some("fullscreen")` the alt-screen
+    /// one. All three are distinct — "let it choose" is not "classic".
     #[serde(default)]
     pub tui_mode: Option<String>,
-    /// Effort level: None = default, Some("low"|"medium"|"high")
+    /// Saved `/effort` level: `None` = unset, otherwise one of
+    /// `"low" | "medium" | "high" | "xhigh"`. Written to settings.json as
+    /// `effortLevel` (**not** `effort`, which Claude Code has never read).
     #[serde(default)]
     pub effort: Option<String>,
-    /// Disable auto-scroll in fullscreen TUI mode
+    /// Disable auto-scroll in fullscreen TUI mode. Held in the *disabled* sense
+    /// because Claude Code's `autoScrollEnabled` defaults to `true`, so the
+    /// zero value of this field has to mean "leave it on".
     #[serde(default)]
     pub auto_scroll_disabled: bool,
-    /// Enable focus mode (collapsed tool output)
+    /// Collapse tool output to one-line summaries. Written to settings.json as
+    /// `viewMode: "focus"`; there is no `focusMode` key in Claude Code.
     #[serde(default)]
     pub focus_mode: bool,
     /// Show thinking summaries in responses
     #[serde(default)]
     pub show_thinking_summaries: bool,
-    /// Enable session recap when returning to a session
+    /// Turn the session recap **off**.
+    ///
+    /// Held in the disabled sense for the same reason as `auto_scroll_disabled`,
+    /// and the rename from the old `enable_session_recap` is load-bearing rather
+    /// than cosmetic. Claude Code's recap is on by default, so the old field was
+    /// inverted: switching it on was a no-op and switching it off did nothing at
+    /// all. Reusing the name with the opposite meaning would have read every
+    /// stored `enable_session_recap: false` — which is what every project that
+    /// never touched the control holds — as "the user turned the recap off" and
+    /// silently disabled it for all of them. A new name lets the old key be
+    /// ignored, which lands every existing project on the correct default.
     #[serde(default)]
-    pub enable_session_recap: bool,
+    pub session_recap_disabled: bool,
     /// Strip credentials from subprocess environments
     #[serde(default)]
     pub env_scrub: bool,