docs(localdb): phase 2 truth pass across both repos

Normative first: Component-StoreAndForward.md:83 specified the whole chunked,
ack-confirmed SfBufferSnapshotChunk resync protocol, which Phase 2 deleted. It
is rewritten rather than removed — the failure modes it reasoned about still
exist, they are just bounded differently — and it now states the
duplicate-delivery bound explicitly: a message can be delivered twice only when
the OLD primary delivered it and the status change had not yet replicated when
the gate flipped. One flush interval plus the in-flight ack, and unlike the old
model it does NOT grow with backlog depth or with how long a node was absent.
The N1 directional-authority and N5 orphan-row hazards are recorded as
structurally gone, not merely unguarded.

Frame-size known-issue amended: its 2026-06-26 resolution replaced the
intra-site hop with notify-and-fetch; Phase 2 then deleted notify-and-fetch
itself, so the 128 KB Akka frame constraint no longer applies to that hop in
any form. Successor ceiling recorded (4 MB gRPC cap via MaxBatchSize, which
batches by ROW COUNT), including that the failure mode differs — an oversized
gRPC message is rejected, not silently dropped.

Deployment docs gain the two operational constraints that have no home in code:
a site pair must be stopped and started TOGETHER (the SfBufferSnapshot compat
handler that made a mixed-version pair converge went with the replicator, and a
mixed pair now diverges silently), and a node offline beyond TombstoneRetention
can resurrect deleted rows on rejoin.

Both CLAUDE.md files corrected — each still said Phase 2 was NOT started.

Definition of done closed: build 0 warnings, all 10 suites green (3509 tests,
0 failures, 0 skips). Two DoD items needed amending rather than ticking: the
stale-symbol grep still matches 4 lines, all deliberate comment prose recording
what was deleted (a literal zero would delete the explanations that stop the
old design coming back), and the live gate has 10 evidence items, not the 9 the
checklist claimed.

Deletes the phase2 resume-state scratch doc, which said to delete it on landing.

Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts

docs/plans/2026-07-19-localdb-adoption-phase2.md.tasks.json

@@ -88,8 +88,8 @@
     {"id": 17, "subject": "Task 17: Config-key cleanup (incl. ConfigFetchRetryCount; 10 appsettings files)", "status": "completed", "classification": "standard", "blockedBy": [16], "note": "As planned. DEVIATION: deploy/wonder-app-vd03/appsettings.Site.json sits under a GITIGNORED deploy/ tree, so its edit is local-only and must be repeated on the box at deploy time. Comment style is // (JSONC) rather than \"_comment_\" keys: every one of these files already contains // comments and .NET's json config reader accepts them, and a _comment_ key inside a bound section is a phantom config entry. Both relaxations pinned by the INVERSE of the test they replace (Site_MissingSiteDbPath_IsAccepted..., EmptySqliteDbPath_IsAccepted...), each verified red with the old rule restored. DatabaseOptionsValidator needed no change - it was already null-tolerant/blank-rejecting, which is exactly migration-only semantics.", "commit": "605e5682"},
     {"id": 18, "subject": "Task 18: Two-node convergence suite for the Phase 2 tables", "status": "completed", "classification": "high-risk", "blockedBy": [17], "note": "DEVIATION: landed as a NEW file LocalDbPhase2ConvergenceTests.cs rather than extending Phase 1's LocalDbSitePairConvergenceTests.cs, and drives the REAL SiteStorageService instead of hand-written SQL - possible only post-cutover, and what makes the cascade scenario test the shipped transaction rather than a re-creation of it. Scenario 4 was retargeted onto shared_scripts/external_systems/static_attribute_overrides because the plan's version overlapped LocalDbConfigConvergenceTests' N1 scenario almost exactly; the union-survives property is per-table, so re-proving it on untouched tables is the non-redundant half. Cascade test carries a never-removed control instance (absence assertions otherwise cannot distinguish 'cascade converged' from 'node B lost these tables'). Non-vacuity PROVEN as mandated: with the 8 RegisterReplicated calls commented out, 4 failed / 0 passed; restored, 20/20 across the three LocalDb suites.", "commit": "15013156"},
     {"id": 19, "subject": "Task 19: Rig configuration (MaxOplogRows/MaxOplogAge + MaxBatchSize per D6)", "status": "completed", "classification": "small", "blockedBy": [17], "note": "MaxBatchSize 500->16 (D6: row-count batching x ~70 KB production config_json vs the 4 MB gRPC cap; 16 => ~1.1 MB worst case). MaxOplogRows 1M->250,000 and MaxOplogAge 7d->2d from the soak's 0.80 rows/sec (~69k/day). Tighter-than-default is SAFE because a cap breach prunes + sets needs_snapshot (graceful snapshot resync), not data loss - the Task 1 finding that the plan's stop condition was weaker than written. site-b/site-c left unreplicated so default-OFF stays proven side by side.", "commit": "921edab4"},
-    {"id": 20, "subject": "Task 20: Live gate on the docker rig (10 evidence items)", "status": "pending", "classification": "high-risk", "blockedBy": [18, 19], "note": "Includes the post-cutover oplog drain-under-churn check (evidence 10) that Task 1 cannot measure pre-cutover. Sample DBs via throwaway copies (snap() helper), never host-side sqlite3 on live files; metrics on :8084 in-container."},
-    {"id": 21, "subject": "Task 21: Documentation truth pass", "status": "pending", "classification": "standard", "blockedBy": [20]}
+    {"id": 20, "subject": "Task 20: Live gate on the docker rig", "status": "completed", "classification": "high-risk", "blockedBy": [18, 19], "note": "ALL 10 CHECKS PASS. Evidence: docs/plans/2026-07-19-localdb-phase2-live-gate.md. Key blocker found and fixed mid-run: external systems reach a site ONLY via ArtifactDeploymentService, which `instance deploy` never invokes - `deploy artifacts` was needed both to deliver the probe harness and to propagate the owed ExternalSystemDefinitions restore. THREE METHOD CORRECTIONS to the plan: (1) its instruction to run DB checks host-side against the bind mounts is UNSAFE - host sqlite3 poisons the container WAL; copy the db/-wal/-shm triplet and query the copy. (2) `docker exec ... curl` cannot scrape metrics (no curl in aspnet:10.0) and with 2>/dev/null the failure is silent - it nearly became a false 'metrics missing' finding; use a network-sharing curl sidecar. (3) checks needing S&F load need CachedCall, not Call. CAVEATS recorded not glossed: check 2's zero-count is vacuous alone (legacy source was also empty) and rests on the ABSENCE of CDC triggers; check 7's native_alarm_state leg was empty live and is covered only offline; check 10's sampling is coarse and the real rise/drain evidence comes from check 6's 0->4->0.", "commit": "158e79bb"},
+    {"id": 21, "subject": "Task 21: Documentation truth pass", "status": "completed", "classification": "standard", "blockedBy": [20], "note": "Both CLAUDE.md files + Component-StoreAndForward.md:83 (normative resync paragraph rewritten for CDC, stating the duplicate-delivery bound explicitly: limited to messages the OLD primary delivered whose status change had not yet replicated when the gate flipped - one flush interval plus in-flight ack, and it does NOT grow with backlog depth or absence duration) + components/{StoreAndForward,SiteRuntime,Host}.md + the frame-size known-issue (amended: Phase 2 deleted notify-and-fetch itself, so the 128KB Akka frame constraint is gone from the intra-site hop entirely; successor ceiling is the 4MB gRPC cap via MaxBatchSize, and note the failure mode differs - oversized gRPC is REJECTED, not silently dropped) + deployment topology-guide.md and installation-guide.md (D5 stop-both-together, D2 TombstoneRetention resurrection bound). DoD closed: build 0 warnings, all 10 suites green (3509 tests, 0 failures). DoD grep nuance recorded in the plan: 4 matches remain in src/ and are all deliberate COMMENT prose explaining what was deleted - a literal 'no matches' would delete the explanations that stop someone re-introducing the old design.", "commit": null}
   ],
   "knownFlakes": [
     {