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+# V3 Phase 15 G9F - Placement Intent to Authority Bridge Mini-Plan
+
+Date: 2026-05-02
+Status: architect draft; code must not start until §1.A is accepted
+Branch target: `p15-g9d/volume-lifecycle-intent` or successor branch off `phase-15`
+Scope: first bridge from placement intent facts toward authority publication
+
+## 0. Why this needs a mini-plan
+
+G9D-A through G9D-E intentionally stayed on the observation/product-intent side:
+
+```text
+DesiredVolumeStore
+NodeInventoryStore
+PlanPlacement
+PlacementIntentStore
+ReconcilePlacement
+LifecycleSnapshot
+```
+
+None of those layers publishes authority or readiness.
+
+G9F is the first possible crossing from placement intent to assignment. That is a truth-domain boundary. A placement intent says "these slots look like candidates"; it does not prove that those slots are fresh, reachable, safe to assign, or data-continuity-ready.
+
+Therefore G9F must be a controller bridge with explicit verification, not a direct `PlacementIntent -> Publisher` shortcut.
+
+## 1. Product goal
+
+Allow blockmaster to use product registration/discovery facts as input to future assignment decisions, while preserving the P15 anti-pattern rule:
+
+```text
+placement intent alone cannot mint authority
+```
+
+## 1.A Architect bindings
+
+Proposed bindings for ratification:
+
+1. **Bridge shape:** G9F implements a verify-only controller bridge that produces `AssignmentCandidate` / `PlacementAuthorityRequest`-style internal decisions. It does not call `Publisher` directly in the first slice.
+2. **Required intersection:** every placement slot considered for authority must intersect with fresh observation for the same `server_id` and usable `data_addr` / `ctrl_addr`.
+3. **No ready shortcut:** existing `ReplicaInventory` can justify reusing a local durable identity, but cannot imply `replica_ready`.
+4. **No frontend shortcut:** desired volume + placement intent cannot make `frontend_primary_ready`.
+5. **Single publisher seam:** actual epoch/endpoint-version minting remains in authority publisher/controller code, not `cmd/blockmaster` and not lifecycle stores.
+6. **Negative oracle:** a placement intent with no fresh observation must not produce any authority-shaped output.
+7. **Scope stop:** if G9F needs proto/control API changes or modifies publisher apply logic, stop and split into G9F-2 after review.
+
+## 2. Inputs and outputs
+
+### Inputs
+
+- `PlacementIntentStore`: desired slot plan from G9D.
+- Observation store / heartbeat facts: fresh runtime address facts.
+- Existing topology/controller supportability predicates where reusable.
+
+### Output, first slice
+
+An internal non-authority result:
+
+```text
+VerifiedPlacement{
+  volume_id
+  slots[] {
+    server_id
+    source
+    replica_id?       // existing-replica reuse only
+    data_addr
+    ctrl_addr
+    verified_by = observation
+  }
+}
+```
+
+Forbidden fields on first-slice output:
+
+```text
+Epoch
+EndpointVersion
+Assignment
+Ready
+Healthy
+Primary
+```
+
+## 3. Algorithm sketch
+
+For each `PlacementIntent`:
+
+1. Validate slot count equals `DesiredRF`.
+2. For each slot:
+   - locate fresh observation for the intended server / replica slot;
+   - require non-empty `DataAddr` and `CtrlAddr`;
+   - if source is `existing_replica`, require local inventory identity match;
+   - if source is `blank_pool`, mark as create-needed, not ready.
+3. If any slot lacks fresh observation, return `NotVerified`.
+4. If all slots verify, return `VerifiedPlacement`.
+5. Do not mint authority.
+
+## 4. TDD plan
+
+### A. Negative tests first
+
+1. `TestG9F_PlacementIntentWithoutObservation_DoesNotVerify`
+   - placement intent exists;
+   - no heartbeat/observation;
+   - output is `NotVerified`;
+   - no authority-shaped fields.
+
+2. `TestG9F_PlacementIntentWithStaleObservation_DoesNotVerify`
+   - observation expired by freshness window;
+   - no verified placement.
+
+3. `TestG9F_PlacementIntentWithWrongReplicaInventory_DoesNotVerify`
+   - existing-replica slot names `r2`;
+   - inventory says different store/size/state conflict;
+   - no verified placement.
+
+4. `TestG9F_VerifiedPlacement_IsNotAuthorityShaped`
+   - structural guard forbidding `Epoch`, `EndpointVersion`, `Assignment`, `Ready`, `Healthy`, `Primary`.
+
+### B. Positive tests
+
+5. `TestG9F_BlankPoolIntentWithFreshObservation_VerifiesCreateNeededSlot`
+   - blank capacity selected by G9D;
+   - fresh node observation provides address;
+   - verified output marks slot as create-needed, not ready.
+
+6. `TestG9F_ExistingReplicaIntentWithFreshObservation_VerifiesReuseCandidate`
+   - existing replica inventory and observation agree;
+   - verified output carries data/ctrl addresses and replica id.
+
+### C. Integration guard
+
+7. `TestG9F_VerifiedPlacementDoesNotChangePublisherState`
+   - run verifier against a real master host with lifecycle stores;
+   - assert `Publisher().VolumeAuthorityLine(volumeID)` remains absent.
+
+## 5. Implementation boundary
+
+Allowed:
+
+- new package or file under `core/lifecycle` or `core/host/master` for verification;
+- pure structs and tests;
+- read-only use of lifecycle stores and observation facts;
+- no proto change.
+
+Forbidden:
+
+- no `Publisher.Apply` call;
+- no `AssignmentInfo` construction in lifecycle package;
+- no `AssignmentFact` construction in lifecycle package;
+- no engine mode update;
+- no frontend readiness change;
+- no CLI/API verb that triggers authority minting.
+
+## 6. Close criteria
+
+G9F first slice closes when:
+
+- all tests in §4.A and §4.B pass;
+- integration guard §4.C passes;
+- structural guard appears in code;
+- docs state that verified placement is still not authority.
+
+## 7. Follow-up after first slice
+
+Only after the verify-only bridge is green:
+
+1. decide whether verified placement becomes input to existing `TopologyController`, a new placement controller, or a publisher directive adapter;
+2. write a separate mini-plan for the authority-minting slice;
+3. add a negative test that observation-only and placement-only each fail, while placement+fresh-observation can request authority.
+