feat(sse,tui): bump spec pin to v0.28.0 + AffectUpdate event (v0.11.0)

Spec pin moved 55101e9 (v0.19.0) → da93ca7 (v0.28.0); vendored
conversation-api-spec.md + conversation_api.contract.md re-snapshotted
from Worldtree at the new SHA. The only material delta consumed in
this bump is Worldtree #204's affect_update SSE event surface.

Wire layer (sse_client.py):
- New AffectUpdate dataclass: sse_id / status / turn_id / snapshot
  (snapshot is None for status="scheduled")
- Added to Event union + _envelope_for_type dispatch branch
- Without this, ratatoskr would crash on any persona-enabled turn
  from a v0.28.0 server (unknown SSE event type → ValueError)

TUI layer (tui.py):
- AffectUpdate routes through the v0.10.0 audit pipeline only — one
  debug-pane line per arrival with dominant_emotion + PAD for
  status="current", lightweight status+turn_id for status="scheduled"
- No transcript / tools / thinking pane writes — the persona UX shape
  (Persona TabPane vs sticky header line) is deferred to a separate
  bump pending operator direction

Tests: 2 new wire-layer tests for current+scheduled parsing + 2 new
presenter audit tests for routing and audit-line shape.

Not yet consumed: GET /agents/{id}/persona_state endpoint (step 2 of
the integration plan).

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.10.0"
+version = "0.11.0"
 description = "Worldtree Conversation API debug TUI — multi-pane observability dashboard"
 readme = "README.md"
 requires-python = ">=3.12"
@@ -42,9 +42,9 @@ Repository = "https://gitea.phasefinal.com/vh/ratatoskr"
 # Ratatoskr is built against Worldtree at this commit; the vendored
 # spec snapshot in docs/ reflects that SHA.
 [tool.ratatoskr.spec-pin]
-worldtree-spec-rev = "55101e909abcd2219833266b6f905c5bc956e0f0"
-worldtree-version = "v0.19.0"
-pinned-on = "2026-05-20"
+worldtree-spec-rev = "da93ca7cf613f1dc229a7a44d07fc1d7efc78e25"
+worldtree-version = "v0.28.0"
+pinned-on = "2026-05-25"
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/ratatoskr"]