[Docs] Remove CLAUDE.md and name work branches feat/<topic> #144

User instructions (2026-10-03): remove CLAUDE.md (Claude Code reads AGENTS.md directly) and repoint whatever refers to it; name branches feat/<topic> (never work/), merge with --delete-branch, delete local branches and worktrees, and periodically delete branches merged into develop, keeping only main, develop, release (and release-* snapshots). The 39 merged work/* remote branches were already deleted.

Done when: CLAUDE.md is gone, AGENTS.md §4/§17 and PROJECT.md describe the new rules, no doc tells agents to use work/ branches.