docs: add per-tool API documentation and fix parity gaps

- Create 53 per-tool VitePress documentation pages with accurate
  parameters from Zod schemas, example requests, and response formats
- Add root llms.txt for LLM-friendly repo browsing
- Fix OpenAPI spec: add auth and 422 error schemas to
  edit-metadata/inspect and strip-metadata/inspect sub-routes
- Fix tool count inconsistency (52 -> 53) across landing site,
  e2e tests, and local docs
- Rename color-adjustments.ts to adjust-colors.ts to match tool ID
- Update VitePress sidebar with all 8 tool categories and top nav

apps/docs/tools/resize.md

@@ -0,0 +1,69 @@
+---
+description: Resize images by pixels, percentage, or with fit modes.
+---
+
+# Resize
+
+Resize images by specifying exact pixel dimensions, a percentage scale factor, or a fit mode that controls how the image adapts to the target dimensions.
+
+## API Endpoint
+
+`POST /api/v1/tools/resize`
+
+Accepts multipart form data with an image file and a JSON `settings` field.
+
+## Parameters
+
+| Parameter | Type | Required | Default | Description |
+|-----------|------|----------|---------|-------------|
+| width | integer | No | - | Target width in pixels (max 16383) |
+| height | integer | No | - | Target height in pixels (max 16383) |
+| fit | string | No | `"contain"` | How the image fits the dimensions: `contain`, `cover`, `fill`, `inside`, `outside` |
+| withoutEnlargement | boolean | No | `false` | Prevent upscaling if image is smaller than target |
+| percentage | number | No | - | Scale by percentage (e.g. 50 for half size) |
+
+At least one of `width`, `height`, or `percentage` must be provided.
+
+### Fit Modes
+
+- **contain** - Resize to fit within the dimensions, preserving aspect ratio (may leave empty space)
+- **cover** - Resize to cover the dimensions, preserving aspect ratio (may crop)
+- **fill** - Stretch to exactly match dimensions (ignores aspect ratio)
+- **inside** - Like `contain`, but only downscales, never upscales
+- **outside** - Like `cover`, but only downscales, never upscales
+
+## Example Request
+
+```bash
+curl -X POST http://localhost:1349/api/v1/tools/resize \
+  -H "Authorization: Bearer si_your-api-key" \
+  -F "file=@photo.jpg" \
+  -F 'settings={"width": 800, "height": 600, "fit": "contain"}'
+```
+
+Resize by percentage:
+
+```bash
+curl -X POST http://localhost:1349/api/v1/tools/resize \
+  -H "Authorization: Bearer si_your-api-key" \
+  -F "file=@photo.jpg" \
+  -F 'settings={"percentage": 50}'
+```
+
+## Example Response
+
+```json
+{
+  "jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
+  "downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/photo.jpg",
+  "originalSize": 2450000,
+  "processedSize": 980000
+}
+```
+
+## Notes
+
+- Maximum dimension is 16383 pixels on either axis (Sharp/libvips limit).
+- Output format matches the input format. HEIC, RAW, PSD, and SVG inputs are automatically decoded before processing.
+- EXIF orientation is auto-applied before resizing.
+- The `withoutEnlargement` flag is useful for batch processing where some images may already be smaller than the target.