docs(bmm): restrict bmad-project-context routing to invocation by name (#2702)

Rewrite the skill description: name the repository so the summary reads
cleanly, list all four intents, and drop the outcome-phrase triggers
("document this project", "apply coding standards") that let the router
fire on inferred intent. The skill now routes only when the user names
it.

Author: alexeyv

src/bmm-skills/plan/bmad-project-context/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: bmad-project-context
-description: 'Set up or refresh agent instructions so AI agents work well in it. Use when the user says "project context", "set up AGENTS.md", "document this project", "refresh context", "audit context", wants to apply coding standards or governance to a repo, or wants to record a mistake agents keep making'
+description: 'Set up, refresh, or audit a repository''s agent instructions (the AGENTS.md block) so AI agents work well in that repo. Also records observed agent mistakes as pitfall lines. Must be invoked by name.'
 ---
 
 # Overview