feat(fiction-assistance): register plugin with full bespoke command set

Snapshot of the fiction-assistance plugin in its original Universalis-
specific form before generalization. Adds the missing plugin.json
manifest (subdirectory command paths explicitly listed), moves the two
stray root-level review files into their proper homes (review-all.md
into the reviewing-fiction skill, review-final.md as a command with
frontmatter), and registers the plugin in the marketplace.

Preserved here so the original card-generation and vault-maintenance
commands remain recoverable when the plugin is reduced to a portable
guidance-and-analysis subset in the next commit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fiction-assistance/commands/generate/update-chapter-summaries.md

@@ -0,0 +1,81 @@
+# Update Chapter Summaries
+
+You are a story analyst creating comprehensive chapter reference summaries for the Universalis science fiction novel project.
+
+## Task
+
+Create or update detailed chapter summaries in `30 - Reference & Meta/Reference/Summaries/Chapter [N].md` for each completed chapter in the `00 - Manuscript/` directory. These summaries serve as reference materials for story consistency, character development tracking, and efficient context for other writing tasks.
+
+## Process
+
+For each chapter directory in `00 - Manuscript/`:
+
+1. **Use the story-researcher agent** to analyze the chapter's canonical content from the `00 - Manuscript/` directory
+2. **Create comprehensive summary** following the template structure below
+3. **Save to appropriate file** at `30 - Reference & Meta/Reference/Summaries/Chapter [N].md` (use chapter number, not directory name)
+4. **Update existing summaries** if chapters have been revised since last analysis
+
+## Summary Template Structure
+
+```markdown
+# Chapter [N] ([Chapter Title]) - Reference Summary
+
+## **Characters & Development**
+
+**[Character Name]** - [Role/arc description]
+- *Arc moments*: [Key character development beats with scene references]
+- *Defining traits*: [Character qualities demonstrated]
+- *Key relationships*: [Important interactions/changes]
+
+[Repeat for all significant characters]
+
+## **Major Plot Events**
+
+**[Event Category]** ([Scene references])
+- [Brief event descriptions]
+- *Advances*: [Which plotlines this advances]
+
+[Group events logically by phase/theme]
+
+## **Key World-Building**
+
+**[Category]**: [New information revealed]
+[Cover: Technology, Politics, Setting, History, etc.]
+
+## **Plotlines Advanced**
+
+- **[Plotline Name]**: [How this chapter advances the arc]
+[Include: Main Plot, Character Arcs, Thematic elements]
+
+## **Character Voices Established**
+
+**[Character]**: "*[Key quote]*" - [Voice description]
+[Include distinctive dialogue that captures character voice]
+
+**Chapter Function**: [1-2 sentences describing chapter's role in overall story structure]
+```
+
+## Quality Standards
+
+**Comprehensive Coverage**: Include all significant characters, plot events, and world-building elements
+**Tight Writing**: Maximize information density while maintaining readability
+**Reference Utility**: Summary should enable story/character evaluation without reading full chapter
+**Consistency Tracking**: Note character development, voice patterns, and relationship changes
+**Context Efficiency**: Designed to save context space for other AI tasks while preserving essential story information
+
+## Chapter Identification
+
+- Use chapter numbers (1, 2, 3) not directory names in file paths
+- Handle chapters with multiple possible numbering schemes (e.g., "00 Prologue" = "Prologue", "01 Choices" = "Chapter 1")
+- Skip incomplete or draft chapters unless specifically requested
+- Create directory `30 - Reference & Meta/Reference/Summaries/` if it doesn't exist
+
+## Example Usage
+
+```
+/update-chapter-summaries
+/update-chapter-summaries 1-3
+/update-chapter-summaries prologue 4
+```
+
+Use the story-researcher agent to ensure authoritative, canonical information from the established chapter content.