feat(vault): add vault skill for Claude read/write access to Obsidian notes

.claude/skills/vault/SKILL.md

@@ -0,0 +1,88 @@
+---
+name: vault
+description: Read and write notes in ginnoir's self-hosted Obsidian vault (CouchDB obsidian-livesync backend at obsidian.ginnoir.com). Use when loading persistent context for a session, saving new context, writing a note, or querying vault contents. The vault is the canonical persistent-context store across Claude sessions.
+---
+
+# vault
+
+Obsidian vault backed by CouchDB (obsidian-livesync) at `obsidian.ginnoir.com`.
+
+## Credentials
+
+```
+Endpoint : https://obsidian.ginnoir.com
+DB       : obsidian
+User     : admin
+Password : couchdb_obs_p4ss_7x9k   (also in stacks/notes/stack.env)
+```
+
+## Document format
+
+Each note is a CouchDB document:
+
+| Field  | Meaning |
+|--------|---------|
+| `_id`  | Vault-relative path, e.g. `claude/Context.md` or `Projects/homelab.md` |
+| `data` | Raw markdown content |
+| `type` | `"plain"` for regular notes |
+| `ctime`/`mtime` | Unix ms timestamps |
+| `size` | Byte length of `data` |
+
+Slashes in `_id` must be URL-encoded as `%2F` in requests.
+
+## Read all notes
+
+```powershell
+ssh -o BatchMode=yes ginnoir@valhalla 'docker exec couchdb curl -sf "http://admin:couchdb_obs_p4ss_7x9k@localhost:5984/obsidian/_all_docs?include_docs=true"'
+```
+
+Returns JSON with `rows[].doc.data` = markdown for each note.
+
+## Read one note
+
+```powershell
+# e.g. claude/Context.md
+ssh -o BatchMode=yes ginnoir@valhalla 'docker exec couchdb curl -sf "http://admin:couchdb_obs_p4ss_7x9k@localhost:5984/obsidian/claude%2FContext.md"'
+```
+
+## Write / update a note
+
+Shell escaping inside SSH is treacherous with JSON. The reliable pattern is:
+
+1. Write JSON to `/tmp/note.json` on valhalla
+2. `docker cp` it into the container
+3. `curl -d @/tmp/note.json` from inside the container
+
+```powershell
+# Step 1 — get current _rev
+$rev = (ssh -o BatchMode=yes ginnoir@valhalla 'docker exec couchdb curl -sf "http://admin:couchdb_obs_p4ss_7x9k@localhost:5984/obsidian/claude%2FContext.md"' | python -c "import sys,json; print(json.load(sys.stdin)['_rev'])")
+
+# Step 2 — write JSON to valhalla /tmp
+$json = @{_rev=$rev; data="# My Note`n`nContent"; type="plain"; ctime=0; mtime=0; size=10} | ConvertTo-Json
+$json | ssh ginnoir@valhalla "cat > /tmp/note.json"
+
+# Step 3 — copy to container and PUT
+ssh -o BatchMode=yes ginnoir@valhalla '
+  docker cp /tmp/note.json couchdb:/tmp/note.json
+  docker exec couchdb curl -sf -X PUT \
+    "http://admin:couchdb_obs_p4ss_7x9k@localhost:5984/obsidian/claude%2FContext.md" \
+    -H "Content-Type: application/json" -d @/tmp/note.json
+'
+```
+
+## Load context at session start
+
+```powershell
+ssh -o BatchMode=yes ginnoir@valhalla 'docker exec couchdb curl -sf "http://admin:couchdb_obs_p4ss_7x9k@localhost:5984/obsidian/claude%2FContext.md"' | python3 -c "import sys,json; print(json.load(sys.stdin)['data'])"
+```
+
+## Key notes
+
+| Path | Purpose |
+|------|---------|
+| `claude/Context.md` | Claude's persistent context: ongoing projects, preferences, session notes |
+| `Home.md` | Vault index / root |
+
+## Notes on valhalla Python
+
+Running `python3` on the valhalla *host* cannot resolve `localhost` (DNS issue in SSH env). Always use `docker exec couchdb curl` (CouchDB's own container) to hit the API — it resolves localhost fine internally.