fix: update Cargo.lock and clean registry adapter stubs

Lockfile updated for registry deps. Go and OCI registry adapters
simplified to match Cargo adapter patterns.

fix(kin-cli): align mcp::start() call signature after global-always-o…

…n change

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

feat(kin-mcp): load sibling graphs from global registry

MCP server now loads ALL repo graphs from ~/.kin/registry.toml:
- CWD repo is primary (loaded first)
- Sibling repos loaded from registry, merged into primary
- Sibling entities tagged with [repo_name] prefix in file_origin
- Relations also merged for graph traversal
- Graceful fallback: missing registry or failed loads don't crash

This enables cross-repo semantic_search, find_references, and
impact_analysis across all locally registered Kin repos.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

feat(kin): global registry + cross-repo MCP + assistant sync

Global registry (~/.kin/registry.toml):
- Tracks all local kin repos with path, entity count, last commit
- Updated on every kin init and kin commit
- kin registry: list all registered repos
- kin registry clean: remove stale entries
- Cross-platform (directories crate for home dir)

MCP --global flag:
- kin mcp start --global reads registry, serves cross-repo queries
- kin setup now writes MCP config with --global by default

Assistant sync:
- Ran kin assistant sync on all 5 repos
- AGENTS.md hydrated with kin-first workflow guidance

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

feat(kin): VFS Phase 2 — projection-aware endpoints, write-back, snap…

…shot/eject

Phase 2a: In-memory project_to_bytes() + project_overlay_to_bytes()
  - Pure functions, no disk I/O, 11 tests

Phase 2c: FileLayout cache (ProjectionState) in DaemonState

Phase 2d: Projection-aware VFS endpoints
  - /vfs/read now checks overlay for entity mutations → projects if needed
  - /vfs/tree merges overlay additions
  - POST /vfs/file-changed triggers reconciliation (write-back)
  - GET /vfs/subscribe SSE stub for push invalidation

Phase 2i: Pre-init snapshot + kin eject
  - kin init snapshots repo to .kin/snapshot/ (hardlinks)
  - kin eject restores from snapshot, removes .kin/
  - 7 tests

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix(ci): skip kin-vfs build on Windows (uses Unix sockets)

kin-vfs-daemon uses tokio UnixListener/UnixStream which doesn't exist
on Windows. ProjFS handles VFS natively on Windows. Skip kin-vfs build
for the skip_vector (Windows) matrix entry.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix(ci): pass --no-default-features to Windows build for kin-cli

The vector feature in kin-cli defaults to on, re-enabling kin-db/vector
which pulls in usearch. Windows build needs --no-default-features to
exclude it entirely.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix(kin-cli): gate VectorIndex/semantic search behind vector feature

kin-cli now has a vector feature flag (default: on) that propagates
to kin-db/vector. Without it, run_semantic returns a clear error
message instead of failing to compile.

This enables Windows builds where usearch C++ is disabled.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix(kin): gate Unix-only code for Windows cross-compilation

- kin-core/shims.rs: wrap PermissionsExt + from_mode in #[cfg(unix)]
- kin-daemon/daemon.rs: extract signal handling into cfg-gated helper
  (Unix gets SIGTERM + Ctrl-C, Windows gets Ctrl-C only)

Other crates (auth, update, bench, migrate) were already properly gated.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

fix(ci): also strip features=["vector"] from kin Cargo.toml on Windows

The workspace dep explicitly requests the vector feature, which
re-enables usearch even after we patch kin-db defaults. Now we sed
both files: kin-db's default features AND kin's feature request.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>