feat: add Windsurf IDE adapter for cascade + aichat indexing

[edcet]

Summary

Adds a native Windsurf IDE adapter that indexes both:

• Workspace aichat from ++Windsurf/User/workspaceStorage/*/state.vscdb++ (VS Code chat format)
• Cascade/agent trajectory cache from ++Windsurf/User/globalStorage/state.vscdb++ (base64-encoded protobuf in ++codeium.windsurf++ JSON blob)

Key Design Decisions

• SQLite as authoritative source: The ++/.codeium/windsurf/cascade/*.pb+~+ files are encrypted at rest and are NOT parsed. The unencrypted live data lives in the SQLite cache.
• Hard-reject control characters: ++isCleanString++ rejects any byte < 0x20 (except \n, \t, \r) before the printable-ratio heuristic, eliminating protobuf wire-byte leakage into ++first_query++ and ++content++ fields.
• Model metadata extraction: Populates ++Message.Model++ from trajectory metadata (e.g. ++MODEL_PRIVATE_10++, ++MODEL_SWE_1_5_SLOW++, ++kimi-k2-5++).
• Meaningful project names: Derives session titles from ++cachedTrajectorySummaries++ metadata instead of generic ++windsurf-cascade++ placeholders.

Validation Matrix (10/10)

#	Criterion	Result
1	Build zero errors	✅
2	first_query no corruption	✅ 0 control chars
3	Message.Model populated	✅ 3 models, 3,535 msgs
4	Project names meaningful	✅ 4 distinct titles
5	Role balance ~1:1	✅ 1,767 assistant / 1,768 user
6	No duplicate sessions	✅ 0 duplicates
7	Binary runs	✅
8	index.go integration	✅ 4 points
9	Search clean	✅ No wire-format noise
10	Zero new deps	✅ stdlib only

Testing

• ++go vet ./...++: clean
• ++go test -race -v ./...++: all pass
• ++golangci-lint run --timeout=5m ./...++: clean (after removing unused func)
• ++gofmt -l .++: our delta clean (2 pre-existing unformatted files untouched)

Files Changed

• ++cmd/index_windsurf.go++ (new, ~700 lines)
• ++cmd/index.go++ (integration: 4 insertion points)

Note on Code Signing

The ad-hoc ++codesign -s -++ signature causes macOS SIGKILL when the binary is placed in a Homebrew Cellar path (Gatekeeper/policy interaction). Running unsigned from ++/tmp++ or after removing the signature works correctly. This is a local-dev artifact and does not affect the upstream build (goreleaser handles proper signing).

[0xRaghu]

Thanks for the substantial Windsurf adapter contribution. I pulled this locally and ran go test ./... plus go vet ./...; both passed.

I’m not comfortable merging it today as-is because the adapter is a large heuristic parser over Windsurf’s cached protobuf-like data and does not include fixture/unit coverage for the parsing and classification paths. I also noticed an incremental-indexing integration risk: the top-level index.go gate uses only globalStorage/state.vscdb to decide whether all Windsurf indexing is unchanged, but workspace aichat lives under per-workspace workspaceStorage/*/state.vscdb. If the global DB is unchanged while a workspace chat DB changed, the current top-level gate can skip indexWindsurf(home) entirely, so workspace chats may not re-index.

Suggested next step: remove the global-only skip from the top-level Windsurf block and let indexWindsurfWorkspaceChat / indexWindsurfTrajectoryCache make their own source-specific skip decisions, then add small fixtures or unit tests around parseTopLevelTrajectory, extractCleanStrings, and classifyMessages. Once that is covered, this should be much safer to merge.