Bootstrap Homelab-Docs wiki

Initial documentation of the hubris Proxmox homelab as a cross-linked
markdown wiki. Per-node pages, cross-cutting infrastructure pages, an
investigation log, and an operations cheatsheet. Each node and topic
ends with a Changelog section so changes can be tracked in-place going
forward.

Refreshed against live state on 2026-04-28 — 14 active LXCs (109
syncthing currently stopped) + 1 VM (108 haos). Reflects post-A/B-test
state of the 2026-04-21 hubris crash-loop investigation.

containers/109-syncthing.md

@@ -0,0 +1,26 @@
+# 109 — `syncthing`
+
+Cross-device file sync into `/mnt/library/syncthing`.
+
+## At a glance
+- **Hostname:** `syncthing`
+- **IP:** (none — currently stopped)
+- **Privilege:** **unprivileged** + idmap (for the `media` GID 10000 standard)
+- **Resources:** 2 cores / 2 GiB RAM / 8 GiB rootfs
+- **Mounts:** `/mnt/library` ↔ `/mnt/library`
+- **Status:** **stopped** (was running prior to 2026-04-21).
+
+## Permissions quirk
+The syncthing systemd unit runs with `User=root`, and systemd skips `initgroups()` for `User=root`. Drop-in adds `SupplementaryGroups=media` to `syncthing@.service` so it actually picks up GID 10000. See [media permissions](../infrastructure/media-permissions.md).
+
+## Related
+- [Media permissions](../infrastructure/media-permissions.md)
+- [Hubris host](../hosts/hubris.md)
+
+## Changelog
+
+### 2026-04-28 — wiki entry created
+Initial documentation. Container is currently stopped — reason not yet documented; investigate before re-enabling or destroying.
+
+### 2026-04-20 — joined the `media` GID 10000 standard
+Idmap block + drop-in `SupplementaryGroups=media` on `syncthing@.service`. Config backup: `/root/109.conf.bak.*`.