feat(hooks): track writing contracts + linters in repo

comms-lint.py and comment-lint.py lived only in ~/.claude, which is not
a git repo. Contract prose lived in ~/.claude/CLAUDE.md. Neither survived
a machine rebuild.

Prose moves to claude-md/ fragments, imported via @name.md. Linters move
to hooks/. link.sh and home.nix distribute both. settings.json wiring
stays manual — it holds machine-local MCP/statusline config this repo
must not own.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VaGR6ERGCfzWTtuv2rebGe

bin/link.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Symlink centralized skills/commands into each agent's config dir.
+# Symlink centralized skills/commands/hooks/context into each agent's config dir.
 # For non-Nix machines (NixOS boxes use nix/home.nix instead).
 # Idempotent. Backs up any pre-existing real dir once to <name>.bak.
 set -euo pipefail
@@ -11,6 +11,11 @@ REPO="$(cd "$(dirname "$0")/.." && pwd)"
 CLAUDE_SKILLS="$HOME/.claude/skills"
 CODEX_SKILLS="$HOME/.agents/skills"
 CLAUDE_CMDS="$HOME/.claude/commands"   # commands are Claude-only; Codex ignores
+CLAUDE_HOOKS="$HOME/.claude/hooks"     # hooks are Claude-only
+CLAUDE_HOME="$HOME/.claude"            # CLAUDE.md fragments, pulled in via @name.md
+
+# Per-FILE links, never a whole-dir link: ~/.claude/hooks and ~/.claude itself hold
+# machine-local files this repo does not own, and a dir symlink would hide them.
 
 # backups go OUTSIDE the skill dirs — a *.bak left inside gets discovered as a
 # duplicate skill by both Claude Code and Codex.
@@ -27,7 +32,7 @@ link() { # link <src> <dst>
   echo "linked $dst -> $src"
 }
 
-mkdir -p "$CLAUDE_SKILLS" "$CODEX_SKILLS" "$CLAUDE_CMDS"
+mkdir -p "$CLAUDE_SKILLS" "$CODEX_SKILLS" "$CLAUDE_CMDS" "$CLAUDE_HOOKS"
 
 for d in "$REPO"/skills/*/; do
   name="$(basename "$d")"
@@ -40,4 +45,15 @@ for f in "$REPO"/commands/*.md; do
   link "$f" "$CLAUDE_CMDS/$(basename "$f")"
 done
 
+for f in "$REPO"/hooks/*.py "$REPO"/hooks/*.sh; do
+  [ -e "$f" ] || continue
+  link "$f" "$CLAUDE_HOOKS/$(basename "$f")"
+done
+
+for f in "$REPO"/claude-md/*.md; do
+  [ -e "$f" ] || continue
+  link "$f" "$CLAUDE_HOME/$(basename "$f")"
+done
+
 echo "done."
+echo "hooks still need wiring in ~/.claude/settings.json — see hooks/README.md"