fix(terminal): implement C1 retention budget for hidden parked worktrees

Addresses OOM regressions in hidden parked terminals by force-evicting
worktrees past a retention budget: at most 12 mounted while hidden, none
past 45 minutes (absolute, not exempted by last-active). Eviction is
least-recently-hidden-first. Exempt tabs (unrestorable local PTYs) keep
their panes to avoid orphaning shells; worktrees are force-parked even
if they contain exempts, and their buffers released elsewhere. SSH/remote
worktrees serialize buffers pre-eviction for reveal; local worktrees keep
daemon snapshots. Command Code's done-settle window is transferred across
park/reveal boundaries so the row cannot strand at 'working'. Model probe
on SSH reattach is scoped to park-reveal only, not ordinary reconnects.
Includes new E2E suite proving the budget actually releases memory.

.github/workflows/e2e.yml

@@ -184,7 +184,9 @@ jobs:
     name: ssh docker watcher isolation
     needs: build
     runs-on: ubuntu-latest
-    timeout-minutes: 20
+    # Why 35: the terminal parking + retention specs below add two more
+    # docker-rig tests capped at 240s each on top of the watcher isolation pair.
+    timeout-minutes: 35
 
     steps:
       - name: Checkout
@@ -227,6 +229,13 @@ jobs:
       - name: Run Docker SSH watcher isolation E2E
         run: xvfb-run --auto-servernum env SKIP_BUILD=1 ORCA_E2E_FORWARD_APP_LOGS=1 pnpm run test:e2e:ssh-docker-watcher-isolation
 
+      # Why always(): these specs gate the C1 terminal parking/retention budget
+      # over a real SSH host and run in no other lane, so a watcher-isolation
+      # failure above must not silently skip them.
+      - name: Run Docker SSH terminal parking + retention E2E
+        if: always()
+        run: xvfb-run --auto-servernum env SKIP_BUILD=1 ORCA_E2E_FORWARD_APP_LOGS=1 pnpm run test:e2e:ssh-docker-terminal-parking
+
       - name: Upload watcher isolation traces
         if: failure()
         uses: actions/upload-artifact@v7