Redesign compatibility gate — min uteke version map + runtime feature detection (epic)

[ajianaz]

Part of the Corin v0.4 redesign effort. Single source of truth for which Corin feature requires which uteke version, plus the runtime mechanism so users never hit a silent mismatch.

Compatibility map

Corin 0.4 feature	Min uteke	Issue	Status
Core UI redesign, reading surface, editor, command palette, rails/nav, settings consolidation	0.16.0	#291 #292 #293 #294 #290 #295 #296	planned
Graph add/remove connection	fix release of uteke#1180	#298	blocked — read-only graph OK on 0.16.0
Namespace move/rename/merge/delete UX	API from uteke#1181 (target 0.17.0)	#297	proposed upstream

What

• src/lib/ts/compat.ts: on startup read GET /health → version + api_latest; expose has(feature) driven by endpoint capability probes (not string compare) for gated features, falling back to semver compare when a probe is not distinctive.
• UpgradePrompt.svelte: inline banner + disabled-action tooltip pattern: "Butuh uteke >= X (terpasang: Y)".
• Release checklist step (docs/dev/release.md): bump the map above.

Why

Corin and uteke release independently; endpoint drift (e.g. room/delete response change post-0.16.0) must fail soft with guidance, not with console errors.

Testing

• Unit: probe mocks for each gate (old/new version matrices).
• E2E: against sandbox uteke-serve 0.16.0, all gated actions show UpgradePrompt and nothing throws.
• bun run test + bun run build green.