fix(codex): new-project no longer creates both AGENTS.md and CLAUDE.md

Detect runtime from execution_context path or env vars at workflow start,
then set INSTRUCTION_FILE (AGENTS.md for Codex, CLAUDE.md for all others).
Pass --output $INSTRUCTION_FILE to generate-claude-md so the helper writes
to the correct file instead of always defaulting to CLAUDE.md.

Also add .codex to skipDirs in init.cjs so Codex runtime directories are
not mistaken for project content during brownfield codebase analysis.

Closes #1521

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

commands/gsd/new-project.md

@@ -9,6 +9,10 @@ allowed-tools:
   - Task
   - AskUserQuestion
 ---
+<runtime_note>
+**Copilot (VS Code):** Use `vscode_askquestions` wherever this workflow calls `AskUserQuestion`. They are equivalent — `vscode_askquestions` is the VS Code Copilot implementation of the same interactive question API.
+</runtime_note>
+
 <context>
 **Flags:**
 - `--auto` — Automatic mode. After config questions, runs research → requirements → roadmap without further interaction. Expects idea document via @ reference.

get-shit-done/bin/lib/init.cjs

@@ -276,7 +276,7 @@ function cmdInitNewProject(cwd, raw) {
       '.ex', '.exs',           // Elixir
       '.clj',                  // Clojure
     ]);
-    const skipDirs = new Set(['node_modules', '.git', '.planning', '.claude', '__pycache__', 'target', 'dist', 'build']);
+    const skipDirs = new Set(['node_modules', '.git', '.planning', '.claude', '.codex', '__pycache__', 'target', 'dist', 'build']);
     function findCodeFiles(dir, depth) {
       if (depth > 3) return false;
       let entries;

get-shit-done/workflows/new-project.md

@@ -66,6 +66,29 @@ AGENT_SKILLS_ROADMAPPER=$(node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" a
 
 Parse JSON for: `researcher_model`, `synthesizer_model`, `roadmapper_model`, `commit_docs`, `project_exists`, `has_codebase_map`, `planning_exists`, `has_existing_code`, `has_package_file`, `is_brownfield`, `needs_codebase_map`, `has_git`, `project_path`.
 
+**Detect runtime and set instruction file name:**
+
+Derive `RUNTIME` from the invoking prompt's `execution_context` path:
+- Path contains `/.codex/` → `RUNTIME=codex`
+- Path contains `/.gemini/` → `RUNTIME=gemini`
+- Path contains `/.config/opencode/` or `/.opencode/` → `RUNTIME=opencode`
+- Otherwise → `RUNTIME=claude`
+
+If `execution_context` path is not available, fall back to env vars:
+```bash
+if [ -n "$CODEX_HOME" ]; then RUNTIME="codex"
+elif [ -n "$GEMINI_CONFIG_DIR" ]; then RUNTIME="gemini"
+elif [ -n "$OPENCODE_CONFIG_DIR" ] || [ -n "$OPENCODE_CONFIG" ]; then RUNTIME="opencode"
+else RUNTIME="claude"; fi
+```
+
+Set the instruction file variable:
+```bash
+if [ "$RUNTIME" = "codex" ]; then INSTRUCTION_FILE="AGENTS.md"; else INSTRUCTION_FILE="CLAUDE.md"; fi
+```
+
+All subsequent references to the project instruction file use `$INSTRUCTION_FILE`.
+
 **If `project_exists` is true:** Error — project already initialized. Use `/gsd:progress`.
 
 **If `has_git` is false:** Initialize git:
@@ -1106,18 +1129,18 @@ Use AskUserQuestion:
 
 **If "Review full file":** Display raw `cat .planning/ROADMAP.md`, then re-ask.
 
-**Generate or refresh project CLAUDE.md before final commit:**
+**Generate or refresh project instruction file before final commit:**
 
 ```bash
-node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" generate-claude-md
+node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" generate-claude-md --output "$INSTRUCTION_FILE"
 ```
 
-This ensures new projects get the default GSD workflow-enforcement guidance and current project context in `CLAUDE.md`.
+This ensures new projects get the default GSD workflow-enforcement guidance and current project context in `$INSTRUCTION_FILE`.
 
 **Commit roadmap (after approval or auto mode):**
 
 ```bash
-node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" commit "docs: create roadmap ([N] phases)" --files .planning/ROADMAP.md .planning/STATE.md .planning/REQUIREMENTS.md CLAUDE.md
+node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" commit "docs: create roadmap ([N] phases)" --files .planning/ROADMAP.md .planning/STATE.md .planning/REQUIREMENTS.md "$INSTRUCTION_FILE"
 ```
 
 ## 9. Done
@@ -1138,7 +1161,7 @@ Present completion summary:
 | Research       | `.planning/research/`       |
 | Requirements   | `.planning/REQUIREMENTS.md` |
 | Roadmap        | `.planning/ROADMAP.md`      |
-| Project guide  | `CLAUDE.md`                 |
+| Project guide  | `$INSTRUCTION_FILE`         |
 
 **[N] phases** | **[X] requirements** | Ready to build ✓
 ```
@@ -1220,7 +1243,7 @@ PHASE1_HAS_UI=$(echo "$PHASE1_SECTION" | grep -qi "UI hint.*yes" && echo "true"
 - `.planning/REQUIREMENTS.md`
 - `.planning/ROADMAP.md`
 - `.planning/STATE.md`
-- `CLAUDE.md`
+- `$INSTRUCTION_FILE` (`AGENTS.md` for Codex, `CLAUDE.md` for all other runtimes)
 
 </output>
 
@@ -1242,7 +1265,7 @@ PHASE1_HAS_UI=$(echo "$PHASE1_SECTION" | grep -qi "UI hint.*yes" && echo "true"
 - [ ] ROADMAP.md created with phases, requirement mappings, success criteria
 - [ ] STATE.md initialized
 - [ ] REQUIREMENTS.md traceability updated
-- [ ] CLAUDE.md generated with GSD workflow guidance
+- [ ] `$INSTRUCTION_FILE` generated with GSD workflow guidance (AGENTS.md for Codex, CLAUDE.md otherwise)
 - [ ] User knows next step is `/gsd:discuss-phase 1`
 
 **Atomic commits:** Each phase commits its artifacts immediately. If context is lost, artifacts persist.