feat(install): install _primitives/ + soft pandoc warning

- install.sh:
  - mkdir $AGENTS_DIR/_primitives
  - copy *.sh + README.md from kit _primitives/ with backup_dir guard
  - chmod +x for the primitive scripts
  - extend hooks-copy loop to include tomd-preread.sh (skips if absent,
    preserving back-compat with kits that predate the primitive)
  - soft-warn (not hard-fail) if pandoc is missing — tomd primitive is
    opt-in and works without pandoc for CSV/code/JSON/images
- settings-snippet.json: add PreToolUse(Read) entry for tomd-preread.sh
  with statusMessage. New matcher block (no existing Read matcher).

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

install.sh

@@ -189,12 +189,19 @@ if ! command -v jq >/dev/null 2>&1; then
   err "  apt install jq    (Debian/Ubuntu)"
   exit 1
 fi
+# Soft-warn on pandoc — the tomd primitive works without it for CSV / code /
+# JSON / images, but fails on .docx / .pptx / .html. Opt-in use, so not
+# promoted to a hard-fail.
+if ! command -v pandoc >/dev/null 2>&1; then
+  warn "pandoc not found — tomd primitive will fail on .docx/.pptx. Install: brew install pandoc"
+fi
 
 # --- create target dirs -----------------------------------------------------
 say "creating directories"
 mkdir -p \
   "$AGENTS_DIR/_blocks" \
   "$AGENTS_DIR/_manifests" \
+  "$AGENTS_DIR/_primitives" \
   "$AGENTS_DIR/_templates" \
   "$AGENTS_DIR/_assembler/src" \
   "$AGENTS_DIR/_generated" \
@@ -221,6 +228,15 @@ say "copying shared blocks -> $AGENTS_DIR/_blocks/"
 backup_dir "$AGENTS_DIR/_blocks"
 cp -f "$KIT_DIR/_blocks/"*.md "$AGENTS_DIR/_blocks/"
 
+# --- copy primitives (overwrite; primitives are SSoT from kit) -------------
+if [[ -d "$KIT_DIR/_primitives" ]]; then
+  say "copying primitives -> $AGENTS_DIR/_primitives/"
+  backup_dir "$AGENTS_DIR/_primitives"
+  cp -f "$KIT_DIR/_primitives/"*.sh "$AGENTS_DIR/_primitives/" 2>/dev/null || true
+  cp -f "$KIT_DIR/_primitives/README.md" "$AGENTS_DIR/_primitives/" 2>/dev/null || true
+  chmod +x "$AGENTS_DIR/_primitives/"*.sh 2>/dev/null || true
+fi
+
 # --- copy bridges (overwrite; templates are SSoT from kit) -----------------
 if [[ -d "$KIT_DIR/_bridges" ]]; then
   say "copying bridge templates -> $AGENTS_DIR/_bridges/"
@@ -272,7 +288,8 @@ fi
 # individually rather than the whole directory, so foreign hooks are not
 # dragged into .bak-TIMESTAMP snapshots on every re-run.
 say "copying hooks -> $HOOKS_DIR/"
-for h in assemble-agents.sh assemble-validate.sh no-hand-edit-agents.sh; do
+for h in assemble-agents.sh assemble-validate.sh no-hand-edit-agents.sh tomd-preread.sh; do
+  [ -f "$KIT_DIR/hooks/$h" ] || continue
   backup_file "$HOOKS_DIR/$h"
   cp -f "$KIT_DIR/hooks/$h" "$HOOKS_DIR/$h"
   chmod +x "$HOOKS_DIR/$h"

settings-snippet.json

@@ -30,6 +30,16 @@
             "command": "~/.claude/hooks/no-hand-edit-agents.sh"
           }
         ]
+      },
+      {
+        "matcher": "Read",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "~/.claude/hooks/tomd-preread.sh",
+            "statusMessage": "tomd pre-read auto-convert check..."
+          }
+        ]
       }
     ]
   }