feat(installer): add Windsurf as an agent install target

[SEPURI-SAI-KRISHNA]

Add Windsurf (Codeium / Cognition) as an agent install target.

codegraph install and --target=windsurf now wire CodeGraph into Windsurf's MCP config so Cascade answers code questions through codegraph_explore instead of grepping.

What it does

• Writes mcpServers.codegraph to ~/.codeium/windsurf/mcp_config.json.
• codegraph uninstall removes only the codegraph entry; sibling MCP servers and the rest of the file are preserved.

Design decisions (Windsurf-specific quirks)

• No type field. Windsurf's documented stdio entries are { command, args } (unlike Claude/Cursor's type: "stdio"). Matched the docs — same shape Antigravity uses — and pinned with a
  test.
• Global-only. Windsurf reads only the single user-level mcp_config.json (no project-local file), so supportsLocation('local') returns false with a clear note, mirroring
  Codex/Antigravity. The path is os.homedir()-based on macOS/Linux/Windows alike — no %APPDATA% special case.
• "Refresh" note on install. A valid config isn't loaded live; Windsurf only (re)loads MCP servers when you open the MCP panel and hit Refresh. The install surfaces this so users
  don't think the install silently failed.
• No instructions file (per CLAUDE.md instructions duplicate MCP server instructions — wastes tokens every turn #529 — the MCP initialize response is the single source of truth).
• Deliberately did not inject --path ${workspaceFolder} (Cursor's quirk): Windsurf is global-config-only and there's no evidence it expands that variable, so a speculative injection
  could break the install. Clean standard config is the safe choice; can be revisited if a cwd issue is confirmed.

Files

• src/installer/targets/windsurf.ts (new)
• src/installer/targets/registry.ts, types.ts (register + TargetId)
• tests/installer-targets.test.ts (4 dedicated tests; also auto-covered by the parameterized contract loop)
• CHANGELOG.md (entry under ### New Features)

Testing

• vitest run tests/installer-targets.test.ts → 160/160 pass (parameterized contract suite — install idempotency, sibling preservation, uninstall reverses install, byte-equal
  re-run → unchanged — now runs against windsurf too).
• tsc --noEmit clean; npm run build clean.
• Manual CLI round-trip: install writes the correct shape → seeded a sibling server → uninstall removed only codegraph (sibling survived) → Refresh note surfaces.

Relationship to existing PR #488

There is one open PR that overlaps: #488 "Support 42 new AI agent targets for auto-installer" (by @coder11v), which lists Windsurf among 42 targets. I'm proposing this as a focused
alternative for the Windsurf slice because #488 currently looks hard to land:

• Scope: 43 commits, 46 files, +6,192 / −402.
• Stale: created 2026-05-27, last updated 2026-06-02 (no activity since), with unresolved merge conflicts the author noted they were "working to resolve."
• No maintainer engagement (no review/approval/comments from @colbymchenry).

This PR is a single self-contained target (~180 lines + tests) that slots into the existing contract suite, with zero blast radius on the extraction/resolution/retrieval core. If
#488 lands first, this becomes redundant and can be closed; if not, it delivers Windsurf support on its own.

[SEPURI-SAI-KRISHNA]

Hi @colbymchenry this adds Windsurf as a focused, single-file installer target following the documented targets/ + registry.ts pattern (no type field per Windsurf's docs, global-only config, "click Refresh" note). It slots into the existing parameterized contract suite 160/160 pass plus a CHANGELOG entry, and touches nothing in the extraction/resolution/retrieval core.

Heads-up on overlap: #488 also lists Windsurf among its 42 targets, but it looks stalled (unresolved conflicts, no activity in a few weeks). I'm offering this as a self-contained alternative for just the Windsurf slice happy to close it if #488 lands first, or to rebase if you'd prefer it go in standalone. Let me know which you'd like.

[coder11v]

Hello @SEPURI-SAI-KRISHNA I like the PR. I resolved merge conflicts with PR #488 but neither mine nor other agent target PRs that are open have had any maintainer comment yet, so just a heads up.

[SEPURI-SAI-KRISHNA]

@coder11v thanks for heads-up