# Harden Dashboard Security

## Goal

Close the security gaps identified by the adversarial audit: missing CORS headers, filesystem-sourced task names that bypass validation, and unbounded content-length handling on POST.

## Requirements

### R1. Add CORS headers

The dashboard serves no CORS headers. When bound to `0.0.0.0` (documented in `__main__.py`), any webpage can call the API — including approving/rejecting tasks via POST.

**Fix**: In `DashboardHandler._send_json()` and `_send_error()`, add:
- `Access-Control-Allow-Origin: *` (or configurable via `--cors-origin`)
- `Access-Control-Allow-Methods: GET, POST, OPTIONS`
- `Access-Control-Allow-Headers: Content-Type`
- Handle `OPTIONS` preflight requests for the review endpoint

### R2. Validate filesystem-sourced task names

`discover_tasks()` at `task.py:248` reads directory names directly from `iterdir()`. The `_validate_task_name` regex only applies to API path parsing. A task directory created via `mkdir` with special characters (e.g., quotes, HTML) will be served to the JS client, which injects names into `onclick` attributes and `innerHTML`.

**Fix**: In `discover_tasks()`, skip directories whose names contain characters outside `[A-Za-z0-9_-]`. Log a warning for invalid names.

### R3. Add content-length bound check on POST regardless of R2 from wire-dashboard-config

Even if the caching task isn't done yet, add a quick defensive check:
- If `Content-Length` header > `MAX_POST_BODY`, return 413
- If `Content-Length` header is missing or <= 0, return 400

### R4. Escape task names in JS HTML injection points

In `dashboard.js:renderDetail()`, `renderTaskCard()`, and `renderTimeline()`, task names are interpolated into HTML. While R2 prevents most dangerous names, defense in depth requires:

- Use `escapeHtml()` on `task.display_name` before injection
- Use `data-*` attributes instead of `onclick` for review buttons (pass task name via `dataset`)

### R5. Add `X-Content-Type-Options: nosniff` header

All responses should include `X-Content-Type-Options: nosniff` to prevent MIME type sniffing.

## Acceptance Criteria

- [ ] All API responses include `Access-Control-Allow-Origin` header
- [ ] `OPTIONS /api/task/{name}/review` returns 200 with appropriate CORS headers
- [ ] Task directory named `task-with'quote` is excluded from `discover_tasks()` output
- [ ] Task directory named `valid-task-123` is included
- [ ] POST with `Content-Length: 1000000` returns 413 regardless of caching task status
- [ ] `escapeHtml()` applied to `display_name` in all JS interpolation points
- [ ] Review buttons use `data-task` attribute instead of inline `onclick`
- [ ] All responses include `X-Content-Type-Options: nosniff`

## Non-Goals

- Not adding authentication (the dashboard is a local single-user tool)
- Not adding HTTPS (out of scope for a dev tool)
- Not rate-limiting (single-user, single-threaded server)