feat(rules): project rule + topic suppressions

Lets a project mute individual rules or whole topics from rulebooks it
subscribes to, without unsubscribing the rulebook. Two new association
tables (migration 0060), 4 MCP tools (suppress/unsuppress × rule/topic),
4 REST endpoints, and an inline "× skip" affordance plus collapsed
"Suppressed (N)" section in the project's Rules tab.

get_applicable_rules now emits suppressed_rules and suppressed_topics
(detail objects with rulebook/topic context, not just IDs) so the UI
can render the suppressed list without a follow-up lookup. The main
rules projection grew topic_id and rulebook_id columns for the per-row
suppress affordance.

Project deletion cascades the suppression rows via hard DELETE — they
are pure associations with no soft-delete column, and restoring a
deleted project should start fresh, not inherit stale mutes.

Project-scoped rules (Rule.project_id) are deliberately not suppressible
— delete them with delete_rule instead.

Implements plan-task #187.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/fabledassistant/mcp/tools/tasks.py

@@ -83,6 +83,8 @@ async def get_task(task_id: int) -> dict:
         data["subscribed_rulebooks"] = applicable["subscribed_rulebooks"]
         data["applicable_rules_truncated"] = applicable["truncated"]
         data["project_rules"] = applicable.get("project_rules", [])
+        data["suppressed_rules"] = applicable.get("suppressed_rules", [])
+        data["suppressed_topics"] = applicable.get("suppressed_topics", [])
     return data