Test SyncGuard catch-up protection in Obsidian

test/e2e-obsidian/README.md

@@ -86,6 +86,7 @@ npm run test:e2e:obsidian:focused -- folder-batch
 npm run test:e2e:obsidian:focused -- security-seed-reconnect
 npm run test:e2e:obsidian:focused -- couchdb-http-cache
 npm run test:e2e:obsidian:focused -- replication-status
+npm run test:e2e:obsidian:focused -- sync-guard
 ```
 
 The wrapper accepts only maintained real-Obsidian scenario names; run it with `--help` for the current list. It deliberately does not manage CouchDB, Object Storage, or the P2P signalling relay. Start the required fixture first, or use the complete service-managed suite.
@@ -165,7 +166,7 @@ The Harness also measures ID generation with fixed in-memory data on desktop and
 
 `test:e2e:obsidian:configuration-encryption-sync` requires only the CouchDB fixture configured through `.test.env` or the process environment. It changes the configuration protection key through the real settings interface, restarts the source Vault, and sends a note with E2EE enabled. A fresh Vault receives the encrypted settings without a saved device key, cancels and retries recovery, and restarts with the validated key. Both Vaults then exchange exact note bytes through CouchDB. The scenario checks the restored connection credentials, E2EE passphrase, ID key, remote Metadata, and Chunks, and removes its temporary Vaults, profiles, and unique remote database.
 
-`test:e2e:obsidian:local-suite` builds the plug-in and, unless `LIVESYNC_CLI_COMMAND` selects an external CLI, the local LiveSync CLI. It then runs discovery, smoke, the onboarding invitation, Svelte dialogue mounting, revision repair, settings UI, configuration encryption and its CouchDB synchronisation workflow, the Review Harness, the P2P status pane, Vault reflection, CouchDB upload and manual setup, CLI-to-Obsidian synchronisation, Object Storage upload and Setup URI and QR round trips, P2P Setup URI round-trip, startup scan, provisioned CouchDB Setup URI, two-vault synchronisation, Hidden File Sync, Customisation Sync, internal Metadata Doctor, and setting Markdown export in sequence. Start the local CouchDB, RustFS, and P2P relay fixtures before running it, or use `test:e2e:obsidian:local-suite:services` to let the wrapper stop leftover fixtures, start fresh fixtures, and stop them again after the run.
+`test:e2e:obsidian:local-suite` builds the plug-in and, unless `LIVESYNC_CLI_COMMAND` selects an external CLI, the local LiveSync CLI. It then runs discovery, smoke, the onboarding invitation, Svelte dialogue mounting, revision repair, settings UI, configuration encryption and its CouchDB synchronisation workflow, the Review Harness, the P2P status pane, Vault reflection, CouchDB upload and manual setup, CLI-to-Obsidian synchronisation, Object Storage upload and Setup URI and QR round trips, P2P Setup URI round-trip, startup scan, provisioned CouchDB Setup URI, two-vault synchronisation, SyncGuard catch-up protection, Hidden File Sync, Customisation Sync, internal Metadata Doctor, and setting Markdown export in sequence. Start the local CouchDB, RustFS, and P2P relay fixtures before running it, or use `test:e2e:obsidian:local-suite:services` to let the wrapper stop leftover fixtures, start fresh fixtures, and stop them again after the run.
 
 `test:e2e:obsidian:couchdb-upload` reuses the CouchDB variables from `.test.env` or the process environment. It expects a reachable CouchDB service, creates a unique database, starts from configured plug-in data without the device-local compatibility marker, and verifies that the marker is initialised without a compatibility dialogue, reminder, or runtime pause. It then creates a note in real Obsidian, commits it into the local database, runs one-shot synchronisation, and verifies that the remote database contains both the Metadata document and its Chunks.
 
@@ -293,6 +294,8 @@ The workflow also opens the Customisation Sync dialogue. `--case=visibility` che
 
 `test:e2e:obsidian:received-change-readiness` uses two sequential real Obsidian sessions and isolated CouchDB databases. The source creates ordinary notes and their Chunks; the target starts continuous replication, resets readiness through the public lifecycle service, and receives those documents while its Vault files remain absent. Marking the target ready twice must emit one readiness event and reflect the queued content. A second note remains absent after readiness while database reflecting is explicitly suspended, then appears when that setting is resumed. This focused scenario is outside `test:e2e:obsidian:local-suite`.
 
+`test:e2e:obsidian:sync-guard` uploads six notes and their Chunks from real Obsidian to an isolated CouchDB database, then receives them in two fresh sequential Vaults. It pauses the real receive callback below and at the device-local threshold to verify that the workspace is protected only after enough notes arrive. A held real Vault reflection must retain the overlay after network catch-up completes, beyond the ordinary quiet period, before automatic release and exact content checks. The second target verifies that keyboard input to the focused editor is blocked, clicks **Continue without waiting**, edits an ordinary note through the visible editor while catch-up remains pending, and then verifies every incoming note and the retained local edit after transfer and reflection resume. The scenario restores its runtime hooks in `finally`, retains stage screenshots, and runs in the local suite. It requires CouchDB; no mobile operating-system lifecycle is simulated.
+
 `test:e2e:obsidian:remote-feature-change` starts real Obsidian with continuous CouchDB replication, then changes the remote version document from generation 12 to generation 13 with an unknown feature. It waits for the control document to reach the local database and the active Replicator to retire, checks that another replication is refused, and verifies that an already accepted Vault note remains intact. After restarting the same Vault, the current remote declaration still blocks finite replication and the actual continuous connection attempt. No KV feature history is involved. It is a focused test outside `test:e2e:obsidian:local-suite`; recovery with a future compatible client remains a separate validation boundary.
 
 `test:e2e:obsidian:internal-metadata-migration` enables internal Metadata encryption through the settings UI without Rebuild. It checks unchanged plaintext and rewritten encrypted Hidden File Sync and Customisation Sync Metadata in CouchDB, stable document IDs, mismatch rejection on a second device, and file restoration after aligning settings. It then turns the preference OFF, runs Fast Fetch, and compares content loaded from both Metadata representations and their Chunks while retaining the remote feature declaration. These focused tests use the local CouchDB fixture and are outside `test:e2e:obsidian:local-suite`.