refactor(fiction-assistance)!: reduce to portable guidance and analysis (v2.0.0)

Strip the Universalis-specific vault layout and card-management
machinery. The plugin is now a general-purpose fiction toolkit:
nine commands that take a manuscript path/glob/selection via
\$ARGUMENTS and write their output to the conversation.

Surviving commands, flattened into commands/:
- analyze-story: structural and statistical analysis
- bechdel-test: representation tests (Bechdel + related)
- check-continuity: plot/character/world continuity
- check-voice: per-character voice consistency
- developmental-review: structural feedback on a scene/chapter
- extract-research: world-building and research inventory
- final-review: synthesis of prior-phase reviews
- generate-timeline: chronology with consistency checks
- strategic-review: craft-based critique with priority ranking

Removed (vault and card management): 10 update-*-cards commands,
cleanup-generated, update-changed, update-links,
update-chapter-summaries, validate-story, validate-pdf, score-scenes.
The original bespoke command set is preserved in 65c29d7 for recovery.

Agent (line-editor) and skill (reviewing-fiction) were already
portable and are unchanged. plugin.json no longer needs the
commands subdirectory paths since the layout is flat. Marketplace
description updated to reflect the general-purpose scope.

BREAKING CHANGE: All update-*-cards, cleanup-generated, update-changed,
update-links, update-chapter-summaries, validate-story, validate-pdf,
and score-scenes commands are removed. perform-bechdel-tests is renamed
to bechdel-test. review-final is renamed to final-review.

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

.claude-plugin/marketplace.json

@@ -28,7 +28,7 @@
     {
       "name": "fiction-assistance",
       "source": "./fiction-assistance",
-      "description": "Fiction writing tools — scene analysis, character cards, continuity checks, story statistics, developmental and strategic review. Built around an Obsidian-based novel workspace."
+      "description": "General-purpose fiction-writing guidance and analysis — story stats, continuity and voice checks, representation tests, developmental and strategic review, world-building extraction, timeline construction, and a line-editor agent."
     }
   ]
 }