ops(docker)+test(host)+docs: close register rows 104 + 105 — offline VACUUM recipe applied to the rig; build-time pin that no replicated table is a cascading-FK parent; record row 106 (LocalDb as_of_seq=0 full-snapshot loop)

Row 104: docker/vacuum-site-localdb.sh stops both nodes of a pair together, sets
auto_vacuum=INCREMENTAL + VACUUM on each node volume with integrity_check before/after,
then starts both (DRY_RUN=1 reports). Run on all three rig pairs: six files 0 -> 2, ok,
~11% smaller; site-a replication reconnected with backlog 0 and no watermark change —
VACUUM is replication-invisible (ledger keys by declared PK, oplog seq is INTEGER PRIMARY
KEY AUTOINCREMENT). Topology guide gains the recipe.

Row 105: SiteLocalDbReplicatedTableFkGuardTests builds the real site schema via OnReady
(unreplicated config so 0.3.3's own guard cannot mask the culprit) and asserts every
SiteLocalDbSetup.ReplicatedTables entry (now internal) exists and has no inbound
CASCADE/SET NULL/SET DEFAULT foreign key, with a negative control. The constraint is
enforced at build instead of at the first replicated boot.

Row 106 (found during 104's live verification, NOT caused by it — the identical 127k-row
full snapshot also landed at the earlier deploy restart): SnapshotStreamer.SendAsync stamps
as_of_seq = MAX(seq), which is 0 once a converged sender's oplog is ack-pruned to empty;
a zero-watermark receiver (rebuilt node) is never lifted, so the empty-oplog horizon rule
re-streams a full snapshot on every reconnect. Sender-side one-line fix for LocalDb 0.3.4:
as_of_seq = max(MAX(seq), last_acked_seq).

docs/deployment/topology-guide.md

@@ -357,6 +357,33 @@ a rejoin is safe and self-correcting (verified live: a node stopped and restarte
 with both nodes byte-identical and zero duplicates). Beyond it, rebuild the returning node's
 database from its peer rather than letting it rejoin.
 
+### Site LocalDb files created before 2026-08-20 need a one-off offline VACUUM
+
+SQLite honours `PRAGMA auto_vacuum` only on a table-less database, and until arch-review
+2026-08-19 P4-6 the pragma ran AFTER LocalDb had created its bookkeeping tables — so every site
+file created before that fix is `auto_vacuum=NONE`, and the event-log cap trim's
+`PRAGMA incremental_vacuum` is a silent no-op on it: freed `site_events` pages are reused, but the
+file never shrinks (deferred-work register row 104). Fresh files are now created
+`auto_vacuum=INCREMENTAL`; existing files need a **full `VACUUM` with the pragma set**, which
+rewrites the file and is therefore deliberately NOT done at boot (minutes of exclusive lock on a
+~1 GB file).
+
+Run it in a maintenance window with **both nodes of the pair stopped** (the rule above):
+
+```bash
+DRY_RUN=1 bash docker/vacuum-site-localdb.sh --all   # report: 0 = NONE, 2 = INCREMENTAL
+bash docker/vacuum-site-localdb.sh a                 # one pair: stop both → VACUUM both → start both
+```
+
+The script integrity-checks each file before and after and leaves the pair stopped if the
+post-check fails. It is safe for a replicated pair: `VACUUM` fires no triggers and changes no
+row content, the LWW ledger keys by declared primary key, and the oplog `seq` watermark is an
+`INTEGER PRIMARY KEY AUTOINCREMENT` — all preserved by `VACUUM`. Verified on the docker rig
+2026-08-20 on all three pairs: site-a (replicated) came back `LocalDbReplicationConnected=true`
+with backlog 0 and no schema or watermark change. For a non-docker deployment the recipe is the
+same three statements against the stopped node's `LocalDb:Path` file:
+`PRAGMA auto_vacuum = INCREMENTAL; VACUUM; PRAGMA integrity_check;`.
+
 ### Docker-rig data files on macOS/OrbStack — a virtiofs corruption + availability hazard
 
 **Status: MITIGATED 2026-08-18 (register row 79) — the rigs' data dirs moved to named docker

docs/plans/2026-07-08-deferred-work-register.md

@@ -96,8 +96,9 @@ All 7 fix-now items landed via PLAN-04/05/06/07/08 (verified in review 08 round
 | 101 | ~~**`ApplyingArtifacts_RemovedDataConnection_StopsLiveDclConnection` flaked once — suspected overlay-sweep read racing the artifact-apply write**~~ **RESOLVED 2026-08-17 (`0d3a90a9`) — hypothesis VERIFIED, and the production consequence was WORSE than the row guessed.** The race is real: the snapshot is read off the actor thread but compared against the overlay only when the piped message lands, so a read starting before an artifact apply's store writes can land after `HandleApplyArtifactDataConnectionsToDcl` populated the overlay — its stale (even empty) snapshot then "proves" the just-applied names disappeared. Overlay iteration order explains the exact fingerprint (`PlcA` removed first). Two corrections to the row's guesses: (1) it is NOT "self-healing at the next tick" — the removal evicts the hash slot the overlay's push is gated on, so the next fresh sweep clears the tombstone but re-creates nothing; the stopped connection stays dead **until an instance redeploy**; (2) the mid-write "momentarily not seeing the row" framing was the lesser half — the whole-snapshot staleness (read-before-write, land-after-apply) is the dominant window. Fix: `_definitionsWriteGeneration`, bumped on the actor thread by every artifact apply and captured at every snapshot-read dispatch (boot load + sweep); a result carrying a stale generation is discarded WHOLE — additions included, since a stale row pushed at a live connection would reconfigure it backward and flip-flop with the next fresh read. Deterministic repro fails before the fix (`StaleSweepSnapshot_RacingAnArtifactApply_DoesNotRemoveJustAppliedConnections`); `FreshEmptySweepSnapshot_StillRemovesDisappearedConnections` pins that row-90's legitimate disappearance still fires. SiteRuntime.Tests 647/647; rig redeployed, zero spurious removals/discards at boot, all rig-probe-1 tags Good. Memo §10 records the mechanism. **Postscript 2026-08-18 (merge `505f3569`, agent commit `f02e1166`): extended to the WHOLE snapshot.** The instance-config half had the same TOCTOU, and all three hazards were PROVEN real pre-fix: a stale sweep restarts an instance **backward** (`TryRestartStaleInstance` feeds the snapshot's old `ConfigJson` to `HandleDeploy` — a literal old-config redeploy; pipeline ownership only covers in-flight deploys and the old revision was never claimed), a read-pre-delete/disable **resurrects** a just-stopped instance (delete even clears the sweep claim), and the boot path skews `_deployedInstanceNames`. Fix: one `_storeWriteGeneration` over both tables, bumped at BOTH ends of every actor-thread config mutation (deploy persist, enable, disable, delete, rollback, artifact apply) — both ends because `ApplyDeployment`/`HandleDisable`/`HandleDelete` advance actor state BEFORE the off-thread write, so a completion-only bump (the row-101 original argument, which holds only for the artifact apply) leaves a window. Stale sweep discarded whole; stale boot load re-dispatched, capped at 5 consecutive (then applied with a Warning). CDC/`SiteReconciliationActor` writes deliberately never bump — discovering them is the sweep's purpose. 3 new fail-before tests + 2 fresh-generation guards pinning that row-72/78 legitimate repairs survive; SiteRuntime.Tests 652/652 x3; full suite green (one unrelated Communication.Tests gauge flake → row 102); rig probe: disable/enable/redeploy churn over multiple sweep ticks produced zero self-heal events on either site-a node, tags Good. Memo §11. | Observed by the 2026-08-17 row-100 fix session | Closed 2026-08-17; whole-snapshot extension 2026-08-18. | — |
 | 102 | ~~**`SiteStreamSubscribersActiveGauge_GoesToOneOnConnect_AndBackToZeroOnCancel` is delta-hardened but still flakes — the baseline can't survive other contributors CLOSING**~~ **RESOLVED 2026-08-18 via the preferred option (row-96 pattern).** The survey found the gauge moves ONLY inside the real `SiteStreamGrpcServer.SubscribeInstance` handler, and exactly two test classes drive it: `SiteStreamGrpcServerTests` (the gauge test's own class) and `CleanupVerificationTests` — `GrpcOptionsWiringTests` instantiates the server but never opens a stream, and the client/aggregator suites subscribe against fakes, so none of those can perturb the counter. Both drivers now share the `[Collection("SiteStreamSubscriberGauge")]` xunit collection (comments on both classes + at the baseline poll explain why the relative read alone was insufficient), so no other contributor can close a stream between the baseline capture and the assertions. Verified 4/4 consecutive full-suite runs green (717/717), durations unchanged (22–25 s vs the prior 24 s) — the serialization is free. Original evidence: the test polls `baseline + 1`, but the process-global gauge's baseline is captured ONCE; capture while parallel classes' streams are up → they close → the gauge settles at this test's own 1 and `baseline+1` is unreachable forever — a fixed-baseline delta only survives contributors that hold constant or increase. | Observed 2026-08-18 (one full-suite failure, `Expected: 4, Actual: 1`; 3/3 green in isolation); fixed same day | Closed 2026-08-18. | — |
 | 103 | ~~**Two lesser TTL-bounded circuit-teardown-vs-async-setup races remain in CentralUI**~~ **RESOLVED 2026-08-20 (Low-wave T12, agent commit `c8452136`).** Both instances closed with the Medium-wave T10 take-once discipline: `TransportImport.razor.cs` re-checks disposal after `TryLoadAsync`'s await and releases the import slot through exactly-once ownership (dispose-during-start frees the `BundleSession` slot immediately instead of stranding it for the 30-min TTL), and `Topology.razor` creates its timer under the same post-await re-check so a disposed page leaves no live timer (asserted event-style, not by sleep). Original note: (arch-review 2026-08-19 P6-6's optional tail, deliberately deferred by the fix). The permanent debug-stream leak was closed at `DebugView.razor` + `DebugStreamHub` (dispose-vs-connect take-once pattern, commit `11e623c2`), but two same-family instances with a *different shape* were left: (1) `TransportImport.razor.cs TryLoadAsync` (~:244) — a circuit torn down mid-load strands 1 of the 8 `MaxConcurrentImportSessions` slots until the 30-min `BundleSession` TTL reaps it (partially defeats row 43); (2) `Topology.razor` (~:201-214) — timer created before a disposal re-check. Both are TTL/lifetime-bounded (no permanent leak), which is why they missed the Medium bar. Fix is the same post-await `_disposed` re-check + take-once teardown, but routed through `BundleSession.ReleaseSession`/the wizard-step lifecycle rather than a session-stop call. | Arch-review 2026-08-19 P6-6 remediation (T10 explicitly scoped them out) | Open. | Next CentralUI hardening pass, or opportunistically when either file is next touched. |
-| 104 | **Existing site LocalDb files stay `auto_vacuum=NONE`; `PRAGMA incremental_vacuum` after a cap trim is a no-op on them** | Arch-review 2026-08-19 P4-6 (Low-wave T4, `47f03fe6`) | `auto_vacuum` is only honoured on a table-less database, and `LocalDbSchema.EnsureCreated` had always created LocalDb's bookkeeping tables before `SiteEventLogSchema.Apply` ran — so the pragma had never once taken effect on any real file. The fix (`SiteLocalDbSetup.EnsureAutoVacuumOnFreshFile`, run before `AddZbLocalDb`'s lazy singleton constructs `SqliteLocalDb`) only helps **fresh** files; an unconditional `VACUUM` against a live ~1 GB replicated file was explicitly rejected (long exclusive lock on the active node; the rewrite is CDC-invisible but blocks the sync pump). Every node on the docker rig today predates the fix, so freed `site_events` pages there are reused, not returned to the OS — the storage cap (row 81) still bounds the data volume, only the file size stops shrinking. | Operator-scheduled `VACUUM` in a maintenance window (both nodes of a pair stopped together), or when a site's file is next recreated. |
-| 105 | **Design constraint (not a defect): a LocalDb-replicated table must never be the parent of a row-mutating `ON DELETE` foreign key (`CASCADE`/`SET NULL`/`SET DEFAULT`) from another table** | Arch-review 2026-08-19 P4-7 → LocalDb 0.3.3 (scadaproj `122940c` + review follow-up `9663279`, Low-wave T5) | `LwwApplier` upserts with `INSERT OR REPLACE` under `foreign_keys=ON`, so the implicit delete fires the child action while CDC capture is suppressed — the child rows change on the applying node only and the pair diverges silently. 0.3.3 makes `RegisterReplicated` refuse such a parent at registration (clear exception naming the child FK), which is a BOOT failure for the site node, so this is enforced, not advisory. None of the ten `SiteLocalDbSetup.ReplicatedTables` has any FK today (zero `REFERENCES` on the live rig file). Model cross-table cleanup as explicit application deletes on each table (as the 3-table deploy cascade already does), never as SQLite FK actions. | Whenever a schema change adds a foreign key between site tables, or an eleventh table joins `ReplicatedTables`. |
+| 104 | ~~**Existing site LocalDb files stay `auto_vacuum=NONE`; `PRAGMA incremental_vacuum` after a cap trim is a no-op on them**~~ **RESOLVED 2026-08-20 — recipe shipped and applied to the rig.** New `docker/vacuum-site-localdb.sh` (stop both nodes of a pair together → `PRAGMA auto_vacuum=INCREMENTAL; VACUUM` each volume with integrity checks before/after → start both; `DRY_RUN=1` reports) plus the topology-guide section *Site LocalDb files created before 2026-08-20 need a one-off offline VACUUM*. Run on all three rig pairs: all six files `auto_vacuum 0 → 2`, `integrity_check=ok`, ~11 % smaller (site-a 20.3 → 18.1 MB), site-a replication back `Connected=true`/backlog 0 with no watermark or schema change — the VACUUM was replication-invisible as predicted (ledger keys by declared PK; oplog `seq` is an `INTEGER PRIMARY KEY AUTOINCREMENT`). The same maintenance surfaced the unrelated row 106. Original: | Arch-review 2026-08-19 P4-6 (Low-wave T4, `47f03fe6`) | `auto_vacuum` is only honoured on a table-less database, and `LocalDbSchema.EnsureCreated` had always created LocalDb's bookkeeping tables before `SiteEventLogSchema.Apply` ran — so the pragma had never once taken effect on any real file. The fix (`SiteLocalDbSetup.EnsureAutoVacuumOnFreshFile`, run before `AddZbLocalDb`'s lazy singleton constructs `SqliteLocalDb`) only helps **fresh** files; an unconditional `VACUUM` against a live ~1 GB replicated file was explicitly rejected (long exclusive lock on the active node; the rewrite is CDC-invisible but blocks the sync pump). Every node on the docker rig today predates the fix, so freed `site_events` pages there are reused, not returned to the OS — the storage cap (row 81) still bounds the data volume, only the file size stops shrinking. | Operator-scheduled `VACUUM` in a maintenance window (both nodes of a pair stopped together), or when a site's file is next recreated. |
+| 105 | ~~**Design constraint (not a defect): a LocalDb-replicated table must never be the parent of a row-mutating `ON DELETE` foreign key (`CASCADE`/`SET NULL`/`SET DEFAULT`) from another table**~~ **PINNED 2026-08-20.** Enforcement moved from the first replicated boot to the build: `SiteLocalDbReplicatedTableFkGuardTests` (Host.Tests) builds the real site schema via `OnReady` on an unreplicated config (so 0.3.3's own guard can't mask which FK is at fault), walks `SiteLocalDbSetup.ReplicatedTables` (now `internal`), asserts each exists and has no inbound row-mutating `ON DELETE` FK with the same `sqlite_master JOIN pragma_foreign_key_list` query LocalDb uses, and carries a negative control proving the checker finds a cascading child. The constraint itself stands — the row is kept as its record. Original: | Arch-review 2026-08-19 P4-7 → LocalDb 0.3.3 (scadaproj `122940c` + review follow-up `9663279`, Low-wave T5) | `LwwApplier` upserts with `INSERT OR REPLACE` under `foreign_keys=ON`, so the implicit delete fires the child action while CDC capture is suppressed — the child rows change on the applying node only and the pair diverges silently. 0.3.3 makes `RegisterReplicated` refuse such a parent at registration (clear exception naming the child FK), which is a BOOT failure for the site node, so this is enforced, not advisory. None of the ten `SiteLocalDbSetup.ReplicatedTables` has any FK today (zero `REFERENCES` on the live rig file). Model cross-table cleanup as explicit application deletes on each table (as the 3-table deploy cascade already does), never as SQLite FK actions. | Whenever a schema change adds a foreign key between site tables, or an eleventh table joins `ReplicatedTables`. |
+| 106 | **LocalDb: a converged pair re-streams a FULL snapshot on EVERY reconnect once the sender's oplog has been ack-pruned to empty and the receiver's watermark is 0** | Found 2026-08-20 while verifying row 104 on the rig (site-a-a received the same 127 k-row full snapshot at both the 13:09 deploy restart and the 13:25 VACUUM restart) | Sender-side defect in `SnapshotStreamer.SendAsync`: `as_of_seq = MAX(seq)` of the oplog, which is **0** once the pair has converged and ack-pruning emptied it. The receiver's `SetLastAppliedRemoteSeqAsync` is MAX-guarded (no regression — good), but a peer whose watermark is genuinely 0 (site-a-a was rebuilt after the 2026-08-15 corruption; any wiped/re-imaged node is the same) can never be lifted by an `as_of_seq 0` snapshot, so the 0.1.2 empty-oplog horizon rule (`streamableFrom = last_acked_seq + 1`) sees `0 < 149` as a gap on every handshake and re-streams everything. Rig state: node-b `last_acked_seq=149`, oplog empty; node-a `last_applied_remote_seq=0`. Not a divergence (LWW absorbs the re-delivered rows) but a cost/availability bug — ~1 s and 127 k rows here, minutes and a full-file read on a 1 GB production pair, on every reconnect, until the sender happens to write a new row. Fix is sender-side and wire-compatible: stamp `as_of_seq = max(MAX(seq), last_acked_seq)` (a full snapshot taken now covers every delta ever pruned below `last_acked_seq`), so the receiver's MAX-guarded watermark lifts to 149 and the loop ends; add a pinning test (converged+pruned sender, zero-watermark receiver → exactly one snapshot across two handshakes). Ships as LocalDb 0.3.4. | Next LocalDb release (0.3.4) — small, well-understood, and worth doing before any production pair is rebuilt from its peer. |
 | 68 | ~~**`deploy.sh` run from a git worktree silently rehomes every node's bind-mount data dir**~~ **RESOLVED 2026-08-15 (guard added in the same close-out).** The compose files' bind mounts are relative (`./site-a-node-a/data`), so a deploy from a worktree checkout mounts the worktree's copies — the rig keeps running and looks healthy, but its SQLite stores split from the main checkout's and everything written there is orphaned by the next deploy from main. Bit the rows-46–53 close-out live: the seeding agent's `rig-probe-1` deploy persisted into worktree-homed dirs and "vanished" after the orchestrator's redeploy (no tombstone, no product bug — LWW/tombstone forensics ruled out deletion; the row sat in `.claude/worktrees/…/docker/site-a-node-a/data/site-localdb.db` the whole time). Both `docker/deploy.sh` and `docker-env2/deploy.sh` now refuse to run from a `.claude/worktrees/` path (override: `SCADABRIDGE_ALLOW_WORKTREE_DEPLOY=1`). | Found during the rows-46–53 close-out | Closed 2026-08-15. | — |
 
 ## Resolved (verified against the code 2026-07-10)