a1afbce84c
U2 of the Claude Desktop .mcpb bundle plan. - internal/engine/embed.go embeds the vendored Python tree at build time via //go:embed all:vendored. The engine package owns the embed because Go's directive cannot reach outside its own package directory; sync and gitignore paths are updated to match (internal/engine/vendored/ in place of mcp/vendored/). - internal/engine/extract.go materializes the embed into <cache>/last30days-pp-mcp/<version>/ with a .version sentinel that short-circuits re-extraction. Atomic rename from a .tmp sibling means a partial extraction can never be mistaken for complete. Concurrent first-call extractions serialize behind a per-cache-dir sync.Once. - EnsureUserCache honors a LAST30DAYS_CACHE_DIR env override for locked-down filesystems; the override is named in extract errors. - internal/engine/extract_test.go covers happy path, sentinel skip, version bump, 10-goroutine race, empty-version rejection, unwritable cache parent, and the env override (7 tests, all passing). - A tracked vendored/.gitkeep anchors the embed path so the directive matches even before scripts/sync-engine.sh runs.