Graph Colorize

# Graph Colorize — Color-code the Obsidian Graph View

You are rewriting `$OBSIDIAN_VAULT_PATH/.obsidian/graph.json` so Obsidian's graph view tints nodes by tag, folder, or visibility.

Obsidian stores graph settings in `<vault>/.obsidian/graph.json`. The `colorGroups` array is a list of `{query, color}` pairs; the first matching query wins per node. Queries use Obsidian's search syntax: `tag:#foo`, `path:"concepts"`, `file:foo`, etc. Color is `{"a": 1, "rgb": <packed-int>}` where the int is `(R << 16) | (G << 8) | B`.

## Before You Start

1. **Resolve config** — follow the Config Resolution Protocol in `llm-wiki/SKILL.md` (walk up CWD for `.env` → `~/.obsidian-wiki/config` → prompt setup). This gives `OBSIDIAN_VAULT_PATH`.
2. Confirm `$OBSIDIAN_VAULT_PATH/.obsidian/` exists. If it doesn't, the vault has never been opened in Obsidian — tell the user to open the vault once in Obsidian, then re-run.
3. **Warn the user if Obsidian is likely open**: Obsidian overwrites `graph.json` on close. Tell them to close the vault first, or be ready to reload (Cmd/Ctrl+R) and not touch the graph settings until they reload.

## Step 1: Pick a Mode

Infer the mode from the user's phrasing. If ambiguous, default to **by-tag**.

| User intent | Mode |
|---|---|
| "color by tag", "color my graph", "make it colorful" (default) | `by-tag` |
| "color by folder", "color by category", "color by directory" | `by-category` |
| "highlight visibility", "show internal/pii in graph", "visibility colors" | `by-visibility` |
| User provides explicit mapping (`tag:#foo = red`, or JSON blob) | `custom` |
| "combine tag and visibility" / "both" | `combined` (visibility first, then tag) |

## Step 2: Build the `colorGroups` Array

### Palette (10 distinct, colorblind-friendly colors)

Use in order. If more groups than colors, cycle and add a lightness shift by dividing brightness ~20% via a second pass — or just cap at 10 and tell the user the remaining tags share the "other" color.

| # | Hex | rgb (packed int) | Role |
|---|---|---|---|
| 0 | `#4E79A7` | `5142951` | blue |
| 1 | `#F28E2B` | `15896107` | orange |
| 2 | `#E15759` | `14767961` | red |
| 3 | `#76B7B2` | `7780786` | teal |
| 4 | `#59A14F` | `5873999` | green |
| 5 | `#EDC948` | `15583048` | yellow |
| 6 | `#B07AA1` | `11565217` | purple |
| 7 | `#FF9DA7` | `16751527` | pink |
| 8 | `#9C755F` | `10253663` | brown |
| 9 | `#BAB0AC` | `12234924` | gray |

Every color is wrapped as `{"a": 1, "rgb": <int>}`.

### Mode: `by-tag`

1. Glob `$VAULT_PATH/**/*.md` excluding `_archives/`, `_raw/`, `.obsidian/`, `node_modules/`, `index.md`, `log.md`, `_insights.md`.
2. Parse frontmatter `tags` from each page. Count usage per tag.
3. **Drop `visibility/*` tags** from the frequency list — they are reserved system tags, handled only in `by-visibility` or `combined` mode.
4. Take the top 10 tags by usage. If there are fewer than 10 unique tags, use all of them.
5. For each tag `T` at index `i`: emit `{"query": "tag:#T", "color": palette[i]}`.
6. Optionally, append a final catch-all entry for untagged pages at the end: `{"query": "-[\"tag\":]", "color": palette[9]}` — **skip** if color slot 9 is already taken by a real tag.

### Mode: `by-category`

Use the seven vault top-level folders in this fixed order so colors are stable across runs:

| Folder | Color index |
|---|---|
| `concepts` | 0 (bl