feat(agent-manager): add Gemini CLI agent adapter

[nnhhoang]

Adds a GeminiCliAdapter so ai-devkit agent list and ai-devkit agent detail can discover and inspect running Gemini CLI sessions. The adapter implements the existing AgentAdapter contract (canHandle / detectAgents / getConversation) and registers in every agent.ts entrypoint that composes an AgentManager.

Gemini-specific design

Process detection. Gemini CLI ships as a Node script — bundle/gemini.js with shebang #!/usr/bin/env node. On POSIX systems ps aux therefore reports the process as node /path/to/gemini ... with argv[0] = node, not gemini. Empirically verified on macOS + Volta:

node /Users/foo/.volta/tools/image/node/24.14.0/bin/gemini --help

The adapter reflects this: it requests the Node process pool via listAgentProcesses('node') and keeps only entries whose command line references a gemini entrypoint (gemini, gemini.exe, gemini.js basename in any token). This is the only place the adapter deviates from the argv[0]-basename pattern, and the rationale is documented in JSDoc on both detectAgents and isGeminiExecutable.

Session discovery. Sessions live at ~/.gemini/tmp/<shortId>/chats/session-*.json. <shortId> is opaque (managed by Gemini's project registry), so the adapter iterates every short-id directory and filters by matching session.projectHash — sha256 of the project root Gemini resolved at write time via its .git-bounded findProjectRoot walk. To stay consistent with that walk, the adapter hashes every ancestor of each process CWD as a candidate (candidateProjectRoots) so subdirectory invocations still line up with the session file the Gemini process wrote. Matched sessions populate resolvedCwd on a SessionFile, then the shared matchProcessesToSessions() performs the standard CWD + birthtime 1:1 greedy assignment. Unmatched processes fall back to the process-only AgentInfo shape.

Session parsing. Gemini writes a single JSON object per file (not JSONL) with schema { sessionId, projectHash, startTime, lastUpdated, messages[], directories?, kind }. Each message entry has type of user, gemini, thought, or tool — verified against the vendored bundle source. Visible turns map to user/assistant roles; thought and tool entries are hidden by default and surface as system when --verbose is passed. displayContent takes priority over content when both are present.

Test coverage

37 unit tests:

• canHandle: plain command, full path (case-insensitive), non-match, path-argument false positive, Node-invoked gemini (real Volta install shape), Node-invoked gemini.js bundle entrypoint
• detectAgents: empty, filters non-gemini Node processes out of the pool, process-only fallback, matched-session mapping, cross-project isolation
• discoverSessions: missing ~/.gemini/tmp, empty CWD, projectHash mismatch, malformed JSON skip, session- filename prefix enforcement, parent-of-cwd git-root fallback
• determineStatus: waiting for gemini/assistant entries, running for user, idle past threshold
• parseSession: valid, cached content bypass, missing file, invalid JSON, missing sessionId, empty-summary default, 120-char truncation, lastUpdated priority over entry timestamp
• getConversation: user/assistant routing, verbose system role, missing/malformed files, displayContent priority, empty-content skip, missing type, non-array messages

nx run-many -t build test lint passes — 461 tests across 4 packages, 0 lint errors. Also verified end-to-end by spawning a Node script whose basename resolves to gemini, writing a synthetic session JSON, and calling adapter.detectAgents() directly: process is detected, matched to its session via projectHash, and mapped to an AgentInfo with status, summary, and sessionFilePath populated.

CLI wiring

Registered in all four agent.ts entrypoints (list, detail, stop, focus). The agent detail route map also maps gemini_cli → the new adapter for conversation rendering.

[codeaholicguy]

Did you test the implementation? I checked out the code, but the behavior when running agent list is not as expected; there is no Gemini session even though I already have one running.

[codeaholicguy]

I also suggest that you run this work with dev-lifecycle so that we have the artifact (design, implementation) of this new integration in docs/ai for referencing later.

[codeaholicguy]

Gemini CLI writes content: [{text: "..."}] in practice, but the adapter assumed string. Calling .trim() on an array threw ".trim is not a function". Added resolveContent() to normalize both forms. Affects extractSummary, getConversation, and the GeminiMessageEntry type.