fix(prompts): stop on-disk prompt overrides from freezing forever

EnsureExists blindly seeded ~/.todo-app/prompts/*.md with the bundled
default and never revisited it, so any file created by opening the
Files settings tab shadowed every later default change permanently
(SuggestImprovement/AskUser sections never reached real runs since
2026-06-04). PromptFiles now hashes what a file was seeded/saved with
in prompts/.defaults.json: Classify() tells missing/current-default/
known-past-default/edited apart, ReconcileStaleDefaults() drops files
that only ever matched a superseded default, and real edits are left
alone and surfaced in the Files tab with a diff + reset-to-default
action. QuarantineOrphans() moves stale-named leftovers (agent.md,
planning.md) into prompts/_orphans instead of silently deleting them.
Wired as a Worker startup sweep (PromptFileRecovery) alongside the
existing OrphanRecovery/AttachmentOrphanRecovery services.

src/ClaudeDo.Localization/locales/en.json

@@ -62,7 +62,10 @@
       "retryPrompt": "Retry",
       "dailyPrepPrompt": "Daily prep",
       "weeklyReportPrompt": "Weekly report",
-      "openInEditor": "Open in editor"
+      "openInEditor": "Open in editor",
+      "customizedSection": "CUSTOMIZED",
+      "customizedHint": "These prompts differ from the bundled default and are kept as-is. Reset to pick up future default improvements.",
+      "resetToDefault": "Reset to default"
     },
     "prime": {
       "description": "Prime your Claude usage window by firing a single non-interactive ping on the days you choose, at a chosen time. Only runs while ClaudeDo is open. If the app starts within 30 minutes of the target time, the ping fires immediately.",
@@ -594,7 +597,7 @@
     "onlineInbox": { "workerOffline": "Worker offline — cannot load config.", "saved": "Config saved.", "saveFailed": "Save failed: {0}", "signedIn": "Signed in successfully.", "signedInNoRole": "Signed in, but this account is missing the 'user' role in Zitadel — online sync will be rejected until the role is granted in the ClaudeDo project.", "signInFailed": "Sign-in failed: {0}", "signedOut": "Signed out.", "signOutFailed": "Sign-out failed: {0}" },
     "weeklyReport": { "invalidRange": "Invalid date range.", "generating": "Generating report…", "error": "Error: {0}" },
     "usageMonitor": { "loadFailed": "Couldn't load usage data: {0}" },
-    "filesTab": { "workerOffline": "Worker offline.", "noneBundled": "No default agents bundled.", "allPresent": "All default agents already present.", "restored": "Restored {0} default agent(s).", "restoreFailed": "Restore failed: {0}", "openFailed": "Open failed: {0}" },
+    "filesTab": { "workerOffline": "Worker offline.", "noneBundled": "No default agents bundled.", "allPresent": "All default agents already present.", "restored": "Restored {0} default agent(s).", "restoreFailed": "Restore failed: {0}", "openFailed": "Open failed: {0}", "resetToDefault": "Reset to the bundled default." },
     "sessionSkillsTab": { "installed": "Installed: {0}", "installFailed": "Install failed: {0}", "updated": "Updated.", "updateFailed": "Update failed: {0}", "removed": "Removed.", "removeFailed": "Remove failed: {0}" },
     "worktreesTab": { "workerOffline": "Worker offline.", "removed": "Removed {0} worktree(s).", "blocked": "Cannot force-remove: {0} task(s) still running. Cancel them first.", "removedFrom": "Removed {0} worktree(s) from {1} task(s).", "cleanupFailed": "Cleanup failed: {0}", "resetFailed": "Reset failed: {0}" },
     "worktreesOverview": { "titleAll": "Worktrees", "titleList": "Worktrees — {0}", "listFallback": "list", "cleanupFailed": "Cleanup failed.", "cleanupFailedDetailed": "Cleanup failed: {0}", "removed": "Removed {0} worktree(s).", "discardFailed": "Failed to discard worktree.", "keepFailed": "Failed to keep worktree.", "cannotForceRunning": "Cannot force-remove a running task.", "forceRemoveFailed": "Force remove failed.", "forceRemoveFailedDetailed": "Force remove failed: {0}", "batchProgress": "Merging {0}/{1}…", "batchDone": "Merged {0}, {1} need resolution." },