feat(web): persona pane renders the relation_edge/1 affect model + per-value trend (v0.19.4)

The persona/affect pane read snap.valence (the pre-#265 shape) while Worldtree now
emits snap.relations (relation_edge/1) — so the whole trust/warmth model rendered as
an empty "valence (0)". Now renders the real signal, self-labelled:

- MOOD (PAD, transient): pleasure/arousal/dominance with a one-word descriptor each.
- RELATION → <target> (stage: <relation_context>): trust·ability / benevolence /
  integrity + warmth, each as value + evidence_count (n=) — the durable social model.
- Per-value TREND: Δ-vs-previous (▲/▼) + a unicode sparkline auto-scaled to the value's
  own observed range (flat when sub-0.01 stable, so noise isn't amplified). History
  accumulates client-side, one sample/turn (deduped by emitted_at), capped at 24.
- Falls back to the legacy snap.valence for an older emitter; INV-001 (no fabricated
  Tier-1 fields) + INV-004 (every cell escaped) preserved. Supersedes the #18-D2
  valence assumption + retires the stale "regard dead axis" note.

Verified: render logic asserted in node against the REAL affect.db snapshot + a
perturbed 2nd sample (relations rendered, no "valence (0)", Δ ▲ shown, 2-char
sparkline builds, INV-004 holds). JS syntax clean. No server change (static served
per-request) — refresh + drive turns to watch the trends build.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.19.3"
+version = "0.19.4"
 description = "Worldtree Conversation API debug TUI — multi-pane observability dashboard"
 readme = "README.md"
 requires-python = ">=3.12"