fix: persona_state SET body → canonical {pad:{pleasure,arousal,dominance}} + re-vendor Tier-3 prose (v0.19.7)

worldtree-dev landed the Tier-3 persona/memory/persona_state prose docs
(c9e59ec) — shapes that serialize as freeform Any in the OpenAPI, so the
prose markdown is their source of truth. Re-vendored docs/conversation-api-spec.md
(tolerate_drift markdown pin; worldtree-spec-rev 879cefe→c9e59ec).

Consumer alignment: --set-persona-pad / _set_persona_probe was building
{pad:[list]}, but the canonical POST /sessions/{id}/persona_state body (#317)
is {pad:{pleasure,arousal,dominance}} (named dict). Aligned the probe to the
named dict + a len!=3 guard; updated contract #2's note, the set_persona_state
docstring, and the tests. The set_persona_state wrapper was already correct
(freeform pass-through) — only the CLI probe's body construction drifted.

Suite 602 green. (Also this session: heid-code-review on the #347 slice
returned unanimous zero drift across all three panel arms.)

docs/conversation-api-spec.md

@@ -2699,10 +2699,13 @@ The `turn.started` event always carries `bifrost_override_applied: bool` (True/F
 
 Tier 3 agents are consumer-owned, Worldtree-hosted agents whose
 identity lives at `<user_id>:<agent_name>`. They share the persistent
-session infrastructure with Tier 1 / Tier 2 but layer-specific
-machinery (persona, motivational, memory, valence) is reserved for
-later phases — Phase 2.0 ships baseline addressing + ownership +
-lifecycle only.
+session infrastructure with Tier 1 / Tier 2. The layer-specific
+machinery is now largely active: **`persona` (Phase 2.1, #186),
+`memory` (Phase 2.1, #197), and `motivational` (Phase 2.2, #187) are
+shipped and consumer-settable at define-time.** Only **`valence` remains
+deferred** (non-null → 422 `layer_deferred`). Phase 2.0 shipped the
+baseline addressing + ownership + lifecycle substrate; the subsections
+below document the active layers and their exact validated shapes.
 
 ### Endpoints
 
@@ -2720,11 +2723,13 @@ lifecycle only.
 {
   "agent_name": "wizard",
   "system_prompt": "You are a guided-elicitation wizard...",
-  "model": "glm5-turbo",
-  "persona": null,        // schema-reserved; non-null → 422 layer_deferred
-  "motivational": null,
-  "valence": null,
-  "memory": null
+  "role": "gen-reasoning",       // REQUIRED — a configured model-role (#344), not a raw model id
+  "persona": {                   // active (Phase 2.1) — single-letter OCEAN keys; see "Persona layer"
+    "ocean": {"O": 0.4, "C": 0.6, "E": -0.3, "A": 0.2, "N": 0.5}
+  },
+  "motivational": null,          // active (Phase 2.2) — see "Motivational layer"
+  "memory": null,                // active (Phase 2.1) — see "Memory layer"
+  "valence": null                // still deferred — non-null → 422 layer_deferred
 }
 ```
 
@@ -2756,6 +2761,150 @@ after definition.
 The 201 response includes an advisory `warnings` array (#219) — see
 "Model-assignment warnings" under `PATCH` below.
 
+> **Vendoring note (OpenAPI 2.3.0).** In the frozen OpenAPI 2.3.0 document
+> the `persona` / `motivational` / `memory` / `valence` request fields
+> serialize as **untyped/freeform** — the `POST /agents/define` request
+> model types them as `Any` so the layers can activate without a
+> schema-breaking change. The shapes documented in the subsections below
+> are the **authoritative, validator-enforced** schemas; generate client
+> types from this section, not from the freeform OpenAPI fields.
+
+##### Persona layer (Phase 2.1, #186)
+
+`persona` is **active** as of Phase 2.1. It carries the agent's OCEAN
+personality vector — the durable trait profile from which Worldtree
+derives the mood setpoint (`baseline_pad`) and the mood dynamics
+(gain + relaxation time-constants). Shape:
+
+```json
+"persona": {
+  "ocean": {                     // REQUIRED — exactly these 5 keys, no more, no fewer
+    "O":  0.4,                   // Openness           — float in [-1.0, 1.0]
+    "C":  0.6,                   // Conscientiousness
+    "E": -0.3,                   // Extraversion
+    "A":  0.2,                   // Agreeableness
+    "N":  0.5                    // Neuroticism
+  },
+  "behavioral_notes":  "...",    // optional, ≤ 4096 chars
+  "temperament_notes": "..."     // optional, ≤ 4096 chars
+}
+```
+
+**⚠ OCEAN key format — single-letter, uppercase.** The `/agents/define`
+persona validator requires the `ocean` map to contain **exactly** the five
+uppercase single-letter keys `O, C, E, A, N`. This is a deliberate,
+load-bearing contrast with the transient-character primitive
+(`POST /characters`), whose `ocean` block uses the **spelled-out**
+lowercase keys (`openness`, `conscientiousness`, …). Sending spelled-out
+keys to `/agents/define` returns 422 `persona_ocean_required` ("must
+contain exactly the 5 keys O, C, E, A, N").
+
+> **Fixed in v1.0.0b21 (#348).** Before that build a correctly
+> single-letter-keyed persona was accepted and stored, but resolved to a
+> **neutral** mood, because Worldtree's internal mood-derivation read the
+> spelled-out key form. On v1.0.0b21+ an API-declared persona correctly
+> drives the derived mood setpoint. If you observe neutral mood on a
+> persona-defined agent, confirm the deployment is ≥ v1.0.0b21.
+
+**Range.** Each value is a float in `[-1.0, 1.0]` **signed** — `0.0` is the
+population mean, NOT `[0.0, 1.0]`. Booleans are rejected. Out-of-range → 422
+`persona_ocean_out_of_range`. See [`docs/ocean-traits.md`](ocean-traits.md)
+for the SOTA-grounded 5-band behavioural mapping.
+
+Semantics:
+
+- **Per-agent identity trait** — identical for every end-user and session;
+  immutable post-define (`PATCH {"persona": …}` → 422 `field_not_mutable`).
+  To change the OCEAN profile, delete and re-define the agent.
+- **`extensions` is reserved** — the field exists but must be empty at v0.1;
+  a non-empty `extensions` returns 422 `layer_deferred`.
+- **Sets the mood SETPOINT, not the current mood.** The OCEAN vector fixes
+  `baseline_pad` (the PAD point the mood relaxes toward over time); the
+  *current* per-session mood point is seeded separately via
+  `POST /sessions/{id}/persona_state` (below).
+
+Validation 422 codes: `persona_ocean_required` (missing `ocean`, or keys
+≠ {O,C,E,A,N}), `persona_ocean_out_of_range` (a value outside [-1.0, 1.0], or
+a boolean), `persona_notes_too_large` (a note > 4096 chars), `layer_deferred`
+(non-empty `extensions`), `validation_failed` (unknown top-level field).
+
+##### `POST /sessions/{session_id}/persona_state` — seed the session mood point (Phase 2.1, #186/#189)
+
+Session-scoped mood seed. Sets the *current* PAD mood point for one
+session's bound agent — the starting emotional state, distinct from the
+OCEAN-derived setpoint the mood relaxes toward. Works on any
+persona-enabled session (Tier 1 or Tier 3); most useful for a Tier 3
+durable-agent session that wants to start a conversation from a specific
+mood.
+
+Request:
+
+```json
+{
+  "pad": {
+    "pleasure":  0.42,           // float in [-1.0, 1.0]
+    "arousal":   0.25,
+    "dominance": 0.33
+  }
+}
+```
+
+Response: **`204 No Content`** — no body, no audit event (a session-scoped
+runtime overlay, not a security-relevant event).
+
+Semantics:
+
+- **PAD-only** (#317 Option A). The body accepts exactly one key, `pad`,
+  which must carry all three of `pleasure` / `arousal` / `dominance`, each a
+  float in `[-1.0, 1.0]`. Any other top-level key → 422 `validation_failed`;
+  a missing or malformed `pad` → 422 `persona_seed_invalid`.
+- **Seeds the current mood POINT, not the setpoint.** The OCEAN persona
+  (above) fixes the setpoint the mood relaxes toward; this endpoint sets
+  where the mood *starts*. It does not alter the persona.
+- **Cross-owner sessions return 404** (existence-hiding — a session that
+  isn't yours is indistinguishable from one that doesn't exist).
+- **Pull-over-push precedence (#289).** Once a session's baseline has been
+  rehydrated from an `affect.fetch` (the authoritative cross-session
+  source), a later SET seed is silently ignored — the fetched baseline wins.
+
+There is **no** `POST /agents/{id}/persona_state` — mood is per-session, not
+a durable agent property. `GET /agents/{agent_id}/persona_state`
+short-circuits to 404 for Tier-3 colon-ids: Tier-3 mood is observable only
+over the Bifrost `affect.emit` egress (ADR-0009), never read back through
+the HTTP API.
+
+##### Memory layer (Phase 2.1, #197)
+
+`memory` is **active** as of Phase 2.1 but exposes a deliberately minimal
+surface — the short-term-memory (STM) tier was removed (#197), so the
+historically-present `stm_*` knobs are accept-and-ignore no-ops. Shape:
+
+```json
+"memory": {
+  "embedder_version": "<pinned>",   // optional; MUST equal the library-pinned version
+  "tier3_dreaming":   false         // optional bool, default false
+}
+```
+
+Semantics:
+
+- **`embedder_version`** — optional. If supplied it MUST equal the library's
+  currently-pinned embedder version; a mismatch → 422
+  `embedder_version_mismatch` (with `expected` / `received` in the detail).
+  Omit it to accept the pin. Fixed at define-time and library-pinned
+  thereafter.
+- **`tier3_dreaming`** — optional bool (default `false`); opt-in flag for the
+  Tier-3 dreaming / consolidation path.
+- **`stm_capacity` / `stm_token_budget`** — **deprecated no-ops.** Accepted at
+  define (201) with a `DeprecationWarning`; they carry no runtime effect since
+  the STM tier was removed, and are slated for rejection at the next schema
+  break. Do not send them in new integrations.
+- **`allows_world_scope` — removed.** Sending it → 422 `validation_failed`
+  ("world-shared knowledge belongs in the KB/Mimir plane").
+- **Wholesale-immutable post-define.** `PATCH {"memory": …}` → 422
+  `field_not_mutable` (even for the deprecated `stm_*` fields) — see the
+  PATCH table above.
+
 ##### Motivational layer (Phase 2.2, #187)
 
 `motivational` is **active** as of Phase 2.2 (persona + memory activated in