perf: share one --version probe on activation #239

Why

On activation the extension calls refreshStatusBar(), checkForUpdates(), and registerMcpServerProviderWithBinary(). Each one runs resolvePatchloomStatus() and therefore patchloom --version. A cold managed binary can take several seconds, so first open pays that cost three times.

Suggested fix

Share one in-flight status promise for the activate path (or pass a resolved status into the three callers). Keep a short TTL or clear the cache after managed install/update.

Files

• src/extension.ts
• src/binary/patchloom.ts
• src/status/statusBar.ts
• src/commands/autoUpdate.ts
• src/mcp/register.ts

Not blocking. Noticed in MPI cycle 3 (PR #238).