Add CouchDB cache compatibility controls and native revalidation

test/e2e-obsidian/README.md

@@ -172,9 +172,9 @@ The Harness also measures ID generation with fixed in-memory data on desktop and
 
 The same workflow checks the two remote-activity status boundaries. It first holds a real CouchDB request at the selected fetch implementation and confirms that `🌐N` is visible while `📲` is absent. It then holds the real one-shot replication immediately before its replicator call, confirms that `📲` is visible while no physical request is active, releases it, and requires the finite and bounded activity counts to return to zero, the request and response counts to balance, and both indicators to disappear. Finally, it creates a remote-only chunk, holds the real on-demand fetch immediately before its remote call, makes the same logical active and idle assertions, and verifies that the fetched chunk is written into the local database. These gates make the active states deterministic without replacing the remote request or operation.
 
-`test:e2e:obsidian:couchdb-http-cache` checks replication after rebuilding an encrypted CouchDB remote while an earlier HTTP response remains cached. It enables internal Metadata encryption with Hidden File Sync and Customisation Sync, verifies that the Rebuild replaces the Security Seed and ciphertext while retaining the document revision, and requires the replication pre-check and subsequent sends to succeed without clearing the browser cache. It uses the CouchDB fixture variables, an isolated Vault and profile, and a unique remote database. The raw command uses the current built plug-in by default; `E2E_OBSIDIAN_ARTIFACT_ROOT` can select an exact earlier build for regression comparison.
+`test:e2e:obsidian:couchdb-http-cache` checks replication after rebuilding an encrypted CouchDB remote while an earlier HTTP response remains cached. It enables internal Metadata encryption with Hidden File Sync and Customisation Sync, verifies that the Rebuild replaces the Security Seed and ciphertext while retaining the document revision, and requires the replication pre-check and subsequent sends to succeed without clearing the browser cache. It uses the CouchDB fixture variables, an isolated Vault and profile, and a unique remote database. The raw command uses the current built plug-in by default; `E2E_OBSIDIAN_ARTIFACT_ROOT` can select an exact earlier build for regression comparison. It also verifies the combined startup-time/Seed hash, the default-off headers-only compatibility switch through the visible settings UI, its saved value after reopening, and the resulting request URLs and cache modes in both switch positions.
 
-Run `npm run test:e2e:obsidian:focused -- couchdb-http-cache --request-api` to warm Obsidian's Internal API cache and perform the same workflow with **Use Internal API** enabled. Both modes require an explicit `no-store` read to return the rebuilt ciphertext. The default mode also retains the stale browser-cache assertion; the Internal API mode permits reads during Rebuild to refresh that cache.
+Run `npm run test:e2e:obsidian:focused -- couchdb-http-cache --request-api` to warm Obsidian's Internal API cache and perform the same workflow with **Use Internal API** enabled. Both modes read decoded Metadata through owned Commonlib connections and observe the actual request URLs. They require the cache URL to change after Security Seed replacement and remain stable across new connections with an unchanged Seed, including after Standard Fetch. The ordinary Vault file must retain its expected contents. The final Standard Fetch phase includes Chunk bodies rather than leaving them for on-demand retrieval, so strict local reconciliation can read the file after database replacement. The default mode also retains the stale browser-cache assertion; the Internal API mode permits reads during Rebuild to refresh that cache. Native adapters may return a full body rather than 304 during revalidation.
 
 `npm run test:e2e:obsidian:focused -- chunk-fetch-retry` checks delayed Chunk availability through a real CouchDB service and Obsidian. It creates a Metadata-only remote fixture, starts ordinary one-shot replication with `readChunksOnline`, and inserts the missing Chunk only after a real fetch has returned an empty result. A pass-through observer records the replicator's call times and results without substituting responses or adding waits. The fixture sets the existing minimum request interval to 500 ms to keep the real retry status observable even if finite completion expedites the final probe. The actual status bar must show zero initial requests (`🛄`) and one retry (`🔁`), and both counts must return to zero after delivery ends. On-demand replication excludes Chunk documents from the ordinary pull, so the delayed Chunk must arrive through the observed fetch and produce the exact Vault content.