Sync READMEs and manuals to current script headers

Fix discrepancies found by auditing docs against headers:
- stability_watchdog.sh: wrong variable name (STRIKES → STRIKE_LIMIT) and wrong default (2hr → 12hr) in header
- Watchdogs manual: REBOOT_WINDOW_HRS example value was 2, should be 12
- Transcodes README: transcode_cleanup/manager table said "Every 3 min", should be "Every 7 minutes"
- Tools manual: fallback_state_reset.sh still marked "not yet built" — rewrite section to reflect current script
- Tools manual: claude_startup --setup flag doesn't exist; modes were inverted — fix and add --launch
- Tools README + manual: add docker_prune_images.sh (existed but undocumented)
- Tools manual: add play_state_sync.sh --full to flag reference
- Orchestrators README: arrs_failed_stalled_recovery runs via intermediate_sync (every 4hr), not standalone every 6hr
- Plugin README: add build.sh to scripts table
- Partnership README + manual: add partnership_transfer.sh and onboard_cancel.sh to script tables and flag reference

Partnership/Manual-Partnership.md

@@ -430,6 +430,29 @@ Called automatically by `partnership_manager.sh --offboard`. Can also be run dir
 | `--status` | Show state files, blocklist, SSH key status |
 | `--unblock <hostname>` | Remove hostname from blocklist |
 
+### partnership_transfer.sh
+
+Owner-only. Transfers ownership to the current mirror — swaps roles without moving
+containers. Run via `partnership_manager.sh --transfer --confirm=<phrase>`.
+
+| Flag | Effect |
+|------|--------|
+| `--confirm=<phrase>` | Required confirmation string (from `PARTNERSHIP_TRANSFER_CONFIRM` in master.conf) |
+| `--dry-run` | Preview all steps without executing |
+| `--log` | Verbose per-step output |
+
+### onboard_cancel.sh
+
+Removes SSH keys between hosts in the specified direction. Safe to run at any onboard
+phase — clears the corresponding setup.db flags.
+
+| Flag | Effect |
+|------|--------|
+| `--direction=h1` | Remove HOST1 → HOST2 key (default) |
+| `--direction=h2` | Remove HOST2 → HOST1 key |
+| `--direction=both` | Both directions |
+| `--dry-run` | Preview without making changes |
+
 ### ssh_setup.sh
 
 | Flag | Effect |