feat: narrative format — third-person asterisk-action style with concrete-beat example

Rewrites the closing instruction in assemble_narrative_prompt to enforce
the asterisk-action / interleaved-beat format: actions wrapped in
*asterisks* in third person, dialogue as plain text between beats (no
quote marks), 2-4 short concrete beats per response, no inner monologue
or stage-direction adverbs. Includes a one-line worked example so the
model has a concrete target.

Was producing first-person prose blocks like 'I stare at you... "Well,
that's direct," I murmur'. Target style is short interleaved beats:
'*She turns with soapy hands to cup your face* That's how I know it's
real... *She kisses you softly* You love me when I'm messy...'

Drops narrative_max_tokens 400 -> 250 so the model can't drift into
multi-paragraph monologue. Bumps three test budgets to fit the larger
closing (closing grew ~80 -> ~200 tokens; tests still exercise the
same trim-order behavior, just with proportionally larger budgets).

chat/config.py

@@ -23,9 +23,13 @@ class Settings(BaseModel):
     retrieval_k: int = 4
     narrative_budget_hard: int = 8000
     narrative_budget_soft: int = 6000
-    # Cap on each generated bot response. ~400 tokens ≈ 1–2 short paragraphs.
-    # Bump if you want longer scenes; drop to 200 for terse banter.
-    narrative_max_tokens: int = 400
+    # Cap on each generated bot response. The asterisk-action format
+    # (see ``_closing_instruction`` in chat/services/prompt.py) targets
+    # 2-4 short interleaved action+dialogue beats; ~250 tokens fits that
+    # without leaving room for the model to drift into multi-paragraph
+    # inner-monologue prose. Bump back up if you want longer scenes;
+    # drop to 150 for very terse banter.
+    narrative_max_tokens: int = 250
     # Sampling temperature for narrative generation. 0.7 = grounded /
     # consistent; 0.85 = creative-but-in-character (default); 1.0 = wide
     # variety, can drift; >1.0 = often off-the-rails.

chat/services/prompt.py

@@ -327,12 +327,23 @@ def _build_open_threads_block(threads: list[dict]) -> str | None:
 
 def _closing_instruction(speaker_name: str, addressee_name: str) -> str:
     return (
-        f"Continue the scene as {speaker_name}, in their voice, responding "
-        "naturally. Use *asterisks* for actions and quotes for dialogue. "
-        f"Stay in character. Do not narrate {addressee_name}'s actions or "
-        "thoughts. "
-        "Keep your response to a single beat — one or two short paragraphs "
-        "at most. Don't monologue; leave room for the other person to react."
+        f"Continue as {speaker_name}. Format strictly:\n"
+        f"- Wrap actions and gestures in *asterisks*, third person "
+        f"({speaker_name}/she/he/they) — never first person, never inner "
+        "thoughts inside asterisks.\n"
+        "- Speak dialogue as plain text between action beats, no quote "
+        "marks. Keep speech fragmented, not paragraphs.\n"
+        "- Interleave 2-4 short beats (action, brief speech, action, brief "
+        "speech). Each beat is one concrete gesture or sensory image — no "
+        "explanation, no inner monologue, no stage-direction adverbs.\n"
+        "- Trailing ellipses (...) are fine for emotional weight.\n"
+        "Example: *She turns with soapy hands to cup your face* That's how "
+        "I know it's real... *She kisses you softly* You love me when I'm "
+        "messy... *She rests her forehead against yours* ...and every "
+        "moment in between.\n"
+        f"Show only what {addressee_name} could externally observe of "
+        f"{speaker_name}; never narrate {addressee_name}'s actions or "
+        "thoughts. One response — leave room to react."
     )