Sprint 56h: self-check now expands word count when draft is >10% short of target

- Changed 'STRUCTURAL VALIDATION ONLY' → 'STRUCTURAL VALIDATION AND WORD-COUNT EXPANSION'
- Word floor check now EXPANDS (not just flags) when draft is >10% below chapter_target_words
- Added expansion rules: interiority, sensory grounding, dialogue beats, scene transitions
- Added max_tokens: 32000 and model: power to self-check step for capacity headroom
- Removed 'Expand any description or add sensory detail' from NOT ALLOWED (only applies to existing prose)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/book_chapter.yml

@@ -197,12 +197,14 @@ steps:
       No commentary, no plan headers, no "Pass 1" label.
 
   - type: think
+    model: power
+    max_tokens: 32000
     hint: |
-      SELF-CHECK — STRUCTURAL VALIDATION ONLY
+      SELF-CHECK — STRUCTURAL VALIDATION AND WORD-COUNT EXPANSION
 
-      You have just written a chapter draft. Your job here is narrow: check the draft against
-      the structural checklist below, apply ONLY the corrections that fall within scope, and
-      output the final chapter.
+      You have just written a chapter draft. Your job: check the draft against the structural
+      checklist below, apply all corrections within scope (including word-count expansion if
+      the draft is short), and output the final chapter.
 
       DRAFT TO CHECK:
       {steps[1].text}
@@ -216,8 +218,9 @@ steps:
            project state? Flag any factual break.
         4. FORMATTING: Are there obvious section-break artifacts, duplicate headers,
            or missing chapter title? Flag and fix.
-        5. WORD FLOOR: Is the draft within 10% of {chapter_target_words}? Flag only if
-           critically short (more than 20% under target) — do not expand for style.
+        5. WORD FLOOR: Count the words in the draft. Target is {chapter_target_words} words.
+           - If the draft is MORE THAN 10% under target: EXPAND (see expansion rules below).
+           - If within 10% of target: PASS, output verbatim.
         6. OPENING HOOK: Check the PASS 0 draft prompt ({steps[0].text}) for a line labeled
            "LOCKED PREVIOUS CHAPTER HOOK:". If present, verify the chapter's opening paragraph
            directly resolves it. If not, add a brief resolution sentence at the opening —
@@ -237,14 +240,20 @@ steps:
         - If the chapter is missing its closing hook entirely, add it as a final paragraph
           that matches the hook specified in the draft prompt — no new invention beyond the
           planned hook
+        - WORD COUNT EXPANSION (when draft is more than 10% below {chapter_target_words}):
+          Continue writing new prose scenes AFTER the existing chapter content. Add:
+            * Extended interiority beats between action moments
+            * Sensory grounding — ground each scene location with 1–2 sensory details
+            * Dialogue elaboration — one extra exchange per speaking pair, voice-distinct
+            * Scene transitions — don't jump cuts; write the walk/wait/breath between scenes
+          Keep writing until the full output (original + new) is within 5% of {chapter_target_words}.
+          Obey all voice anti-patterns from PASS 1. Do NOT add new plot beats not in PASS 0.
 
       NOT ALLOWED — do not make any of these changes:
-        - Improve any sentence for prose quality, rhythm, or lyricism
-        - Deepen emotional beats or add interiority
-        - Expand any description or add sensory detail
+        - Improve existing sentences for prose quality, rhythm, or lyricism
         - Reorder scenes or restructure the chapter
-        - Add new metaphors, aphorisms, or quotable lines
-        - Normalize or upgrade the authorial voice
+        - Add new metaphors or aphorisms to existing prose
+        - Normalize or upgrade the authorial voice in existing sentences
 
       OUTPUT FORMAT:
         Start your response with a VALIDATION LOG section:
@@ -253,7 +262,7 @@ steps:
           2. NAMES & POV: [check pass/fail with brief note]
           3. CONTINUITY TERMS: [check pass/fail with brief note]
           4. FORMATTING: [check pass/fail — note any fixes applied]
-          5. WORD FLOOR: [check pass/fail — include word count]
+          5. WORD FLOOR: [PASS/EXPANDED — include word count before and after]
           6. OPENING HOOK: [check pass/fail or N/A]
           7. AUTHOR'S INTENT: [honored / partially missed — note / N/A if no intent set]
           8. CLOSING HOOK LOCK: [locked hook delivered / missing / N/A if not locked]
@@ -261,9 +270,9 @@ steps:
         Then output the separator on its own line:
           ---BEGIN CHAPTER---
 
-        Then output the final chapter text (corrected where structurally required,
-        verbatim everywhere else). Start the chapter directly with the chapter title
-        and first line. No preamble or commentary within the chapter text.
+        Then output the COMPLETE final chapter text (all original prose + any expansion).
+        Start the chapter directly with the chapter title and first line.
+        No preamble or commentary within the chapter text.
 
   # Commit chapter draft now — last_text() = self-check output (step 2). Must come before
   # PASS 3 think so the character-state extraction does not overwrite last_text().