feat(input): add codex automation stack

input/AGENTS.md

@@ -0,0 +1,45 @@
+# Input Agent Guide
+
+## Mission
+Automate the upstream resume customization workflow. Monitor the job-description inbox, combine the base resume and prompt template into a Codex-friendly request, invoke the Codex CLI, and deposit the generated Markdown in a timestamped outbox for human review.
+
+## Directory Responsibilities
+- `resume/` – contains exactly one Markdown resume. Any other count is a fatal configuration error.
+- `ForCustomizing/inbox/` – drop one job-description Markdown at a time to trigger processing.
+- `ForCustomizing/outbox/YYYY/MM/DD/HHMM/` – timestamped folders containing Codex output Markdown (and a copy of the prompt used).
+- `ForCustomizing/processed/YYYY/MM/DD/HHMM/` – archives of job descriptions that Codex processed successfully.
+- `ForCustomizing/failed/` – captures job descriptions when Codex errors or a recoverable issue occurs. Fatal configuration errors still exit the container.
+- `templates/ResumeCustomizerPrompt.md.example` – default instruction block; copy to `ResumeCustomizerPrompt.md` (same folder) to override locally.
+
+## Running the Input Processor
+Launch the stack with the wrapper so files inherit your UID/GID and your local Codex credentials mount in:
+
+```bash
+cd input/Docker
+./run-input-processor.sh up -d
+```
+
+Environment variables you can pass before the command:
+- `CODEX_COMMAND_TEMPLATE` – override the Codex CLI invocation (defaults to `codex prompt --input {prompt} --output {output} --format markdown`).
+- `POLL_INTERVAL_SECONDS` – watcher polling cadence (default `5`).
+- `CODEX_TIMEOUT_SECONDS` – hard timeout for Codex calls (default `600`).
+- `CODEX_CONFIG_DIR` – optional override for the host directory that should mount into `/home/codex/.codex`.
+
+Stop or inspect the stack with:
+
+```bash
+cd input/Docker
+./run-input-processor.sh down
+./run-input-processor.sh logs -f
+```
+
+## Guardrails
+- Ensure only one job description resides in `ForCustomizing/inbox/`. Multiple files cause the container to exit with a fatal error.
+- Keep exactly one resume Markdown in `resume/`. Missing or multiple resumes also terminate the watcher.
+- The container runs as a non-root user matching the caller’s UID/GID. Avoid changing permissions manually inside the mounted directories.
+- Do not edit anything under `output/` from this agent session; treat the downstream pipeline as read-only reference material.
+
+## Troubleshooting
+- If Codex CLI fails, the job description moves to `ForCustomizing/failed/`. Check container logs, adjust the Markdown, then requeue it.
+- Fatal errors (multiple resumes, multiple job descriptions, missing template, or missing Codex binary) stop the container. Resolve the issue and restart via the wrapper.
+- To change the Codex command format, pass a quoted template (e.g., `CODEX_COMMAND_TEMPLATE='codex run --input {prompt} --output {output}' ./run-input-processor.sh up -d'`). The template must include `{prompt}` and `{output}` placeholders.