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+# Workspace Session Restore and Incomplete Worktree Hydration
+
+## Problem
+
+A user reported that after reloading while Orca was updating, their workspaces did not load or were not interactable. The crash-report portion was a separate false positive caused by intentional Electron process teardown. The workspace symptom points at renderer startup state instead: persisted session state can be mounted against an incomplete worktree list.
+
+Orca startup restores state in this order:
+
+1. Load settings.
+2. Load repos.
+3. Fetch all worktrees.
+4. Load persisted UI.
+5. Load the workspace session.
+6. Hydrate terminal, editor, tab, and browser state.
+7. Reconnect persisted terminals.
+8. Mark hydration successful so the session writer can save again.
+
+The risky edge is between steps 3 and 6. `hydrateWorkspaceSession` validates persisted worktree IDs against `worktreesByRepo`. For local repos, a missing worktree ID is treated as deleted and the corresponding saved tabs/workspace state is filtered out.
+
+That is correct only when the worktree list is authoritative.
+
+## Failure Mode
+
+`fetchAllWorktrees` already had a safety gate for the hydration-time purge: if any repo's `worktrees.list` call fails, or if every repo returns an empty list, it defers purging stale `tabsByWorktree` entries. That prevents disk-backed saved tabs from being deleted by a transient Git or IPC problem.
+
+However, startup still continued into session hydration after that degraded fetch. If the saved session referenced local workspaces and `worktreesByRepo` was empty or partial, `hydrateWorkspaceSession` classified those saved local workspaces as invalid in memory.
+
+The likely user-visible result:
+
+- The app shell mounts.
+- The saved active worktree is missing.
+- Terminal/editor/browser state for that worktree may be filtered out.
+- The terminal surface can be hidden or inert because there is no active worktree.
+- If reconnect completes, startup may mark hydration successful, allowing later session writes from the degraded in-memory state.
+
+This matches the report better than a native crash: the app could restart, but the restored workspace model was empty or not actionable.
+
+## Fix
+
+`fetchAllWorktrees` now returns a small startup signal:
+
+```ts
+type FetchAllWorktreesResult = {
+  canHydrateSession: boolean
+}
+```
+
+The result separates two questions that used to be conflated:
+
+- Can the hydration-time stale-state purge run?
+- Is the current worktree map complete enough to validate a persisted session?
+
+Startup now reads the persisted session after UI hydration, then asks `shouldDeferSessionHydrationUntilWorktreesLoaded` whether local session state would be validated against incomplete worktree data. If so, startup throws into the existing session-restore failure path.
+
+That failure path intentionally:
+
+- leaves the persisted session on disk untouched;
+- keeps `hydrationSucceeded` false so the debounced session writer is gated;
+- flips `workspaceSessionReady` so the app shell remains usable;
+- shows the existing sticky "Session restore failed" toast with a restart action.
+
+This is preferable to hydrating a partially empty session and treating it as a successful restore.
+
+## SSH and Floating Terminal
+
+The guard only defers when incomplete worktree hydration would affect local workspace state.
+
+SSH-backed workspaces are exempt because they are reconstructed after SSH reconnect. Their worktree IDs can be valid even when `worktreesByRepo` is initially empty.
+
+The floating terminal is also exempt because it is intentionally not a repo worktree and should not depend on repo worktree discovery.
+
+## Tests
+
+The regression tests cover:
+
+- local workspace session state defers when worktree hydration is incomplete;
+- local editor/browser/tab state keyed by worktree ID also defers;
+- SSH-backed workspaces and the floating terminal can still hydrate during incomplete local worktree startup;
+- `fetchAllWorktrees` reports `canHydrateSession=false` when every repo returns empty during initial hydration;
+- existing purge behavior still defers stale-state cleanup until worktree lists are authoritative.
+
+## Non-Goals
+
+This change does not attempt to retry worktree hydration in place before session restore. A retry loop may be useful later, but the immediate safety requirement is to avoid successful hydration from incomplete data.
+
+This change also does not alter the separate crash-report filtering for Electron SIGTERM process teardown. That fix lives in the crash-reporting path and addresses the false crash prompt, not the workspace restore state.