feat: dual-host setup + find-browse for Codex/Gemini/Cursor

- setup: add --host codex|claude|auto flag, install to ~/.codex/skills/
  when targeting Codex, auto-detect installed agents
- find-browse: priority chain .codex > .agents > .claude (both
  workspace-local and global)
- dev-setup/teardown: create .agents/skills/gstack symlinks for dev mode

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bin/dev-teardown

@@ -3,33 +3,50 @@
 set -e
 
 REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
-SKILLS_DIR="$REPO_ROOT/.claude/skills"
 
-if [ ! -d "$SKILLS_DIR" ]; then
-  echo "Nothing to tear down — .claude/skills/ doesn't exist."
-  exit 0
-fi
-
-# Remove individual skill symlinks
 removed=()
-for link in "$SKILLS_DIR"/*/; do
-  name="$(basename "$link")"
-  [ "$name" = "gstack" ] && continue
-  if [ -L "${link%/}" ]; then
-    rm "${link%/}"
-    removed+=("$name")
-  fi
-done
 
-# Remove the gstack symlink
-if [ -L "$SKILLS_DIR/gstack" ]; then
-  rm "$SKILLS_DIR/gstack"
-  removed+=("gstack")
+# ─── Clean up .claude/skills/ ─────────────────────────────────
+CLAUDE_SKILLS="$REPO_ROOT/.claude/skills"
+if [ -d "$CLAUDE_SKILLS" ]; then
+  for link in "$CLAUDE_SKILLS"/*/; do
+    name="$(basename "$link")"
+    [ "$name" = "gstack" ] && continue
+    if [ -L "${link%/}" ]; then
+      rm "${link%/}"
+      removed+=("claude/$name")
+    fi
+  done
+
+  if [ -L "$CLAUDE_SKILLS/gstack" ]; then
+    rm "$CLAUDE_SKILLS/gstack"
+    removed+=("claude/gstack")
+  fi
+
+  rmdir "$CLAUDE_SKILLS" 2>/dev/null || true
+  rmdir "$REPO_ROOT/.claude" 2>/dev/null || true
 fi
 
-# Clean up empty dirs
-rmdir "$SKILLS_DIR" 2>/dev/null || true
-rmdir "$REPO_ROOT/.claude" 2>/dev/null || true
+# ─── Clean up .agents/skills/ ────────────────────────────────
+AGENTS_SKILLS="$REPO_ROOT/.agents/skills"
+if [ -d "$AGENTS_SKILLS" ]; then
+  for link in "$AGENTS_SKILLS"/*/; do
+    name="$(basename "$link")"
+    [ "$name" = "gstack" ] && continue
+    if [ -L "${link%/}" ]; then
+      rm "${link%/}"
+      removed+=("agents/$name")
+    fi
+  done
+
+  if [ -L "$AGENTS_SKILLS/gstack" ]; then
+    rm "$AGENTS_SKILLS/gstack"
+    removed+=("agents/gstack")
+  fi
+
+  rmdir "$AGENTS_SKILLS" 2>/dev/null || true
+  rmdir "$REPO_ROOT/.agents" 2>/dev/null || true
+fi
 
 if [ ${#removed[@]} -gt 0 ]; then
   echo "Removed: ${removed[*]}"