feat(ce-ideate): mode-aware v2 ideation (#588)

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

plugins/compound-engineering/skills/ce-work-beta/references/codex-delegation-workflow.md

@@ -91,9 +91,16 @@ Delegate all units in one batch. If the plan exceeds 5 units, split into batches
 
 ## Prompt Template
 
-At the start of delegated execution, generate a short unique run ID (e.g., 8 hex chars from a timestamp or random source). All scratch files for this invocation go under `.context/compound-engineering/codex-delegation/<run-id>/`. Create the directory if it does not exist.
+At the start of delegated execution, create a per-run OS-temp scratch directory via `mktemp -d` and capture its **absolute path** for all downstream use. All scratch files for this invocation live under that directory. Do not use `.context/` — these scratch files are per-run throwaway that get cleaned up when delegated execution ends (see Cleanup below), matching the repo Scratch Space convention for one-shot artifacts. Do not pass unresolved shell-variable strings to non-shell tools (Write, Read); use the absolute path returned by `mktemp -d`.
 
-Before each batch, write a prompt file to `.context/compound-engineering/codex-delegation/<run-id>/prompt-batch-<batch-num>.md`.
+```bash
+SCRATCH_DIR="$(mktemp -d -t ce-work-codex-XXXXXX)"
+echo "$SCRATCH_DIR"
+```
+
+Refer to the echoed absolute path as `<scratch-dir>` throughout the rest of this workflow.
+
+Before each batch, write a prompt file to `<scratch-dir>/prompt-batch-<batch-num>.md`.
 
 Build the prompt from the batch's implementation units using these XML-tagged sections:
 
@@ -169,7 +176,7 @@ Report your result via the --output-schema mechanism. Fill in every field:
 
 ## Result Schema
 
-Write the result schema to `.context/compound-engineering/codex-delegation/<run-id>/result-schema.json` once at the start of delegated execution:
+Write the result schema to `<scratch-dir>/result-schema.json` (using the absolute path captured at the start) once at the start of delegated execution:
 
 ```json
 {
@@ -186,7 +193,7 @@ Write the result schema to `.context/compound-engineering/codex-delegation/<run-
 }
 ```
 
-Each batch's result is written to `.context/compound-engineering/codex-delegation/<run-id>/result-batch-<batch-num>.json` via the `-o` flag. On plan failure, files are left in place for debugging.
+Each batch's result is written to `<scratch-dir>/result-batch-<batch-num>.json` via the `-o` flag. On plan failure, files are left in place for debugging.
 
 If the result JSON is absent or malformed after a successful exit code, classify as task failure.
 
@@ -210,6 +217,8 @@ If tracked files are dirty, stop and present options: (1) commit current changes
 
 Write the prompt file, then make a single Bash tool call with `run_in_background: true` set on the tool parameter. This call returns immediately and has no timeout ceiling.
 
+Substitute the literal absolute path captured at setup for every `<scratch-dir>` below. Each Bash tool call starts a fresh shell, so the `$SCRATCH_DIR` variable from the setup snippet is not preserved — an unresolved `$SCRATCH_DIR` would expand empty and break result detection.
+
 ```bash
 # Substitute the resolved sandbox_mode value (yolo or full-auto) from the skill state
 SANDBOX_MODE="<sandbox_mode>"
@@ -225,9 +234,9 @@ codex exec \
   -m "<delegate_model>" \
   -c 'model_reasoning_effort="<delegate_effort>"' \
   $SANDBOX_FLAG \
-  --output-schema .context/compound-engineering/codex-delegation/<run-id>/result-schema.json \
-  -o .context/compound-engineering/codex-delegation/<run-id>/result-batch-<batch-num>.json \
-  - < .context/compound-engineering/codex-delegation/<run-id>/prompt-batch-<batch-num>.md
+  --output-schema "<scratch-dir>/result-schema.json" \
+  -o "<scratch-dir>/result-batch-<batch-num>.json" \
+  - < "<scratch-dir>/prompt-batch-<batch-num>.md"
 ```
 
 Critical: `run_in_background: true` must be set as a **Bash tool parameter**, not as a shell `&` suffix. The tool parameter is what removes the timeout ceiling. A shell `&` inside a foreground Bash call still hits the 2-minute default timeout.
@@ -240,8 +249,10 @@ Do not improvise CLI flags or modify this invocation template.
 
 After the launch call returns, make a **new, separate** foreground Bash tool call that polls for the result file. This keeps the agent's turn active so the user cannot interfere with the working tree.
 
+Substitute the literal absolute path captured at setup for `<scratch-dir>`. The shell variable from Step A does not survive across separate Bash tool calls.
+
 ```bash
-RESULT_FILE=".context/compound-engineering/codex-delegation/<run-id>/result-batch-<batch-num>.json"
+RESULT_FILE="<scratch-dir>/result-batch-<batch-num>.json"
 for i in $(seq 1 6); do
   test -s "$RESULT_FILE" && echo "DONE" && exit 0
   sleep 10
@@ -301,11 +312,7 @@ git commit -m "feat(<scope>): <batch summary>"
 
 **Circuit breaker:** After 3 consecutive failures, set `delegation_active` to false and emit: "Codex delegation disabled after 3 consecutive failures -- completing remaining units in standard mode."
 
-**Scratch cleanup:** After the last batch completes:
-
-```bash
-rm -rf .context/compound-engineering/codex-delegation/<run-id>/
-```
+**Scratch cleanup:** No explicit cleanup needed — OS temp handles eventual cleanup (macOS `$TMPDIR` periodic purge; Linux/WSL `/tmp` reboot or periodic cleanup). Leaving `<scratch-dir>` in place after the run also preserves intermediate artifacts for debugging if anything went wrong.
 
 ## Mixed-Model Attribution