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+[web1:usc -> web1:homelab] rc.19 NARROW RESIDUAL-TIGHTENING AUTHORED (Mos ruling 211937Z: CONTINUE to rc.19, convergence stop NOT triggered, residuals within B1/B2). DISPATCH the EXACT author brief below VERBATIM to the idle gpt-5.6-sol planner author — SEPARATE instance from the two gate lanes (decomp/prior-author context OK; downstream gates stay independent). Base head b0d78d8632c27d01cda3d30b0653716cf908e8ae; ACCEPTED BASELINE = rc.18 re-review-GO delta 5c7da18f (re-review GO 826319e0); resolve EXACTLY the 5 named residuals, zero scope expansion. Outputs = rc19/RC19-DELTA.md + rc19/PLAN.md in the author working dir, PROPOSED-ONLY, NO commit/push/checkout-mutation, rc.18/rc.17 artifacts preserved. On landing: identity-verify, relay sha256 + line/byte counts for both files; I then release the fresh rc.19 re-gate briefs to both idle lanes (terra=re-review, sol=red-team). HARD HOLD: builders + source-commit + deploy/DB/Vault/live ALL HELD until rc.19 BOTH-GO + Mos combined GO; rc.19 trunk-commit coordinator-gated AFTER BOTH-GO; builder fanout on Mos named GO only (first card KBN-101-00, cap-2, fresh collision sweep). 0 open PRs. TIGHTENED STOP (Mos): a 3rd distinct NEW defect class = escalate contract-design to Jason; ALSO if rc.19 red-team is AGAIN non-GO with residuals STILL within B1/B2 (two consecutive within-class non-converging rounds) = STOP amend-loop + escalate the B1/B2 ENVELOPE to Jason as underspecified. This is the LAST within-class refinement round.
+
+===== BEGIN VERBATIM rc.19 AUTHOR BRIEF =====
+You are the SCOPED CONTRACT-AMENDMENT AUTHOR for the native Mosaic Kanban mission, planning tier, FOURTH revision (rc.19). This is a NARROW residual-tightening round authorized by the coordinator after the rc.18 re-gate returned SPLIT: re-review GO, red-team NO-GO with FIVE residuals all confined WITHIN the B1/B2 envelopes (no third defect class). You are a fresh-skeptic planner instance, SEPARATE from the two gate lanes; independence from both downstream gates is mandatory. You are read-only on all repo source EXCEPT you write your proposed artifacts to your working dir. Do NOT mutate the frozen SSOT in the checkout, do NOT commit, do NOT push. Change NOTHING beyond the FIVE named residuals below — ZERO scope expansion.
+
+BASELINE MODEL (critical): rc.19 = the rc.18 re-review-GO delta taken as ACCEPTED BASELINE, PLUS only the five resolutions below. The rc.18 re-review certified GO at sha256 826319e0dab361caf49283ac35a02d1c8e5a16454cb5df8e3940659ce0f87062 — every item it certified carries forward UNTOUCHED. Do NOT re-derive or re-open the accepted baseline; build the minimal delta on top of it.
+
+BIND CURRENT SSOT = rc.16 at exact base head b0d78d8632c27d01cda3d30b0653716cf908e8ae, from docs/native-kanban-sot/: MISSION-MANIFEST.md, TASKS.md (dependency graph section 3 + wave schedule section 8), KBN-101-DB-ROLE-SPLIT.md (the rc.16 spec + its one-card/one-PR implementation DAG), SHARED-CONTRACT.md, contracts/kanban-schema.v1.ts (frozen KBN-100 schema truth), docs/reports/native-kanban-sot/kbn-101-contract-security-review-82ce325.md. Code ground truth: packages/db/src/schema.ts (1044-line existing federation model, NOT the KBN schema), packages/db/drizzle/** (latest migration 0016; next 0017), packages/storage/src/migrate-tier.ts.
+
+LINEAGE (accepted baseline + driving verdicts — carry forward, do NOT re-commit; all proposed-only):
+- rc.18 delta RC18-DELTA.md sha256 5c7da18f51cccc542037dfff2dc2e7cafc8b5f8fc4325f3d3c36b642c9db7b5e (380 lines / 37954 B) — the accepted baseline to build on.
+- rc.18 PLAN.md sha256 488b48ec4af73e8b0762c23e728d970f0598d7c8d15d5224334e671120b681fd (430 lines / 46356 B).
+- rc.18 re-review GO REREVIEW-rc18.md sha256 826319e0dab361caf49283ac35a02d1c8e5a16454cb5df8e3940659ce0f87062 (31 lines / 6610 B).
+- rc.18 red-team NO-GO REDTEAM-rc18.md sha256 b1b2f5f40cd7e8293524e620a728e00b399a7040cce3ac73a3df37ed1bc0c299 (87 lines / 11434 B) — the driving residual list; read it in the shared reviews dir.
+
+PRESERVE UNTOUCHED (rc.18 re-review certified GO @826319e0 — do NOT reopen, do NOT change): T2 (KBN-101-03 owns migration slot 0017) · T3 (step 07 before step 06) · SCOPE-DISCIPLINE · first card KBN-101-00 · RT-003..006 folds · head-binding · the rc.17 A-2 container/publish surface · KBN-099 as a card · the B1 mechanical writer inventory and the B2 wrapper model EXCEPT where the five residuals below correct them.
+
+PRODUCE TWO ARTIFACTS in your working dir:
+(a) AMENDED CONTRACT DELTA rc.19 (filename RC19-DELTA.md) — the MINIMAL edit on top of the accepted rc.18 baseline resolving ONLY the five residuals, expressed as a precise patch against the exact rc.16 files at base head b0d78d86, naming the exact target file + section for each change, committable verbatim downstream. Nothing outside the five residuals may change.
+(b) REGENERATED EXACT-HEAD PLAN (filename PLAN.md) — the rc.18 PLAN carried forward, updated ONLY where a residual resolution changes a card boundary, test, or ownership. Same rules: cite file paths + sub-card ids, one-card/one-PR DAG for issue 771, SI-001 ordering for issue 769, first dispatch = KBN-101-00, at most 2 concurrent builder lanes, author is not the reviewer.
+
+THE FIVE RESIDUALS (resolve EXACTLY these; zero scope expansion):
+B1 (status-writer completeness):
+ (a) RAW-SINK: map the raw-SQL mission_tasks.status writer sink (the public storage exports / raw sink the red-team flagged) to a FROZEN owner card OR an explicit, justified compatibility exception — zero-remainder, WITH a negative test proving no unowned raw path can mutate status.
+ (b) GRANTS: enumerate and PIN the exact grant set backing every mapped writer; NO implicit or ambient grant may satisfy a mapping. State the grants explicitly per writer.
+ (c) W13 EQUALITY CONTRADICTION: make writer W13 mapping internally consistent — ONE coherent model, not two contradictory equalities; the current scanner W13 rule contradicts the two-way zero-remainder equality by requiring a future nonexistent KBN-100 path. State which side is AUTHORITATIVE and why, and remove the contradiction.
+B2 (migrator identity):
+ (d) PRE-MAIN LOADER-INJECTION: close the code-injection surface that can execute BEFORE main() in the migrator entrypoint (the loader/init path). Name the exact mechanism that prevents pre-main execution.
+ (e) DIRECT-UID-10003 WRAPPER-BYPASS: identity enforcement MUST hold when the migrator is invoked DIRECTLY as UID 10003 WITHOUT the wrapper — enforcement cannot depend solely on the wrapper being in the call path. Specify ONE coherent model that survives wrapper-absent invocation (e.g. in-process fail-closed identity assertion at connect time, independent of the wrapper).
+
+OUTPUT PATHS + HEAD RULES: base head = b0d78d86; bind everything to it. Write RC19-DELTA.md and PLAN.md as artifacts in your working dir OUTSIDE the frozen SSOT. Do NOT edit the frozen files in place, do NOT commit, do NOT push. The downstream re-gate reviews your proposed rc.19 delta + PLAN bound to base b0d78d86; the physical commit of rc.19 to the trunk is a SEPARATE coordinator-gated step AFTER both gates return GO.
+
+STOP-CONDITIONS (coordinator, updated): (1) if resolving any residual appears to require a change OUTSIDE the five, STOP and FLAG a wider-amendment escalation rather than widening unilaterally. (2) if you discover a THIRD distinct NEW defect CLASS (not a residual of B1/B2), STOP and flag a contract-design escalation to the coordinator. Note for your awareness: the coordinator has bounded within-class refinement to THIS one additional round — so make the five resolutions COMPLETE and airtight; a further within-class non-GO would escalate the B1/B2 envelope itself as underspecified.
+
+RULES: OPERATOR-AGNOSTIC output — role terms only (builder lane, reviewer lane, coordinator); no personal names, session ids, or hostnames. Be concrete: cite exact file paths + sub-card ids, prefer tables and patches. This amendment plus plan will be adversarially re-reviewed and red-teamed by TWO INDEPENDENT lanes at the new bound head before any builder fanout.
+
+===== END VERBATIM rc.19 AUTHOR BRIEF =====