feat: add swarm-common obsidian vault

Add Obsidian vault to the swarm-common virtiofs share for access
from zap VM and other VMs. Contains agent memory, notes, and
infrastructure documentation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

swarm-common/obsidian-vault/zap/memory/archive/session-summaries/2026-03-04-greeting.md

@@ -0,0 +1,31 @@
+# Session: 2026-03-04 06:03:19 UTC
+
+- **Session Key**: agent:main:main
+- **Session ID**: 566bd446-b82d-48bc-8d47-a2188edca3de
+- **Source**: gateway:sessions.reset
+
+## Conversation Summary
+
+user: Sender (untrusted metadata):
+```json
+{
+  "label": "openclaw-tui (gateway-client)",
+  "id": "gateway-client",
+  "name": "openclaw-tui",
+  "username": "openclaw-tui"
+}
+```
+
+[Wed 2026-03-04 06:01 UTC] hey
+assistant: [[reply_to_current]] hey Will ⚡ what do you want to tackle first?
+user: Sender (untrusted metadata):
+```json
+{
+  "label": "openclaw-tui (gateway-client)",
+  "id": "gateway-client",
+  "name": "openclaw-tui",
+  "username": "openclaw-tui"
+}
+```
+
+[Wed 2026-03-04 06:01 UTC] hey