Adds an instance_history table that records every field change:
- createInstance logs a 'created' event
- updateInstance diffs old vs new and logs one row per changed field
(name, state, stack, vmid, tailscale_ip, all service flags)
- History is stored under the new vmid when vmid changes
New endpoint: GET /api/instances/:vmid/history
The 'timestamps' section on the detail page is replaced with a
grid timeline showing timestamp | field | old → new for each event.
State changes are colour-coded (deployed=green, testing=amber,
degraded=red). Boolean service flags display as on/off.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Stacks are always just production/development — counting them adds
no useful information to the dashboard summary.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds a gear button to the nav that opens a settings modal with:
- Export: GET /api/export returns all instances as a JSON backup file
with a Content-Disposition attachment header
- Import: POST /api/import validates and bulk-replaces all instances;
client uses FileReader to POST the parsed JSON, with a confirm dialog
before destructive replace
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Production images continue to display the semver (v1.x.x). Dev images
built by CI now receive BUILD_VERSION=dev-<7-char-sha> via a Docker ARG,
and app.js skips the v prefix for non-semver strings.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
