test: add unit tests for Gemini CLI adapter

[jpleva91]

What

Unit tests for packages/adapters/src/gemini-cli.ts — previously untested at the adapter level. CLI-level tests existed (cli-gemini-hook.test.ts) but didn't cover the core normalization and response-formatting logic.

Coverage

• resolveGeminiAgentIdentity: no-session fallback, empty/whitespace, hash format and consistency, uniqueness across sessions
• normalizeGeminiCliAction: all 7 tool mappings (WriteFile→Write, EditFile→Edit, ReadFile→Read, Shell→Bash, ListFiles→Glob, SearchCode→Grep, WebSearch→WebFetch), unknown tool passthrough, missing tool_input, source: gemini-cli metadata invariant
• Session ID propagation: payload sessionId, GEMINI_SESSION_ID env var fallback, metadata threading across all tool types
• geminiToActionContext: KE-2 adapter contract — file.write/file.read/git.push/shell.exec action classes, destructive flag, persona pass-through, full ActionContext shape
• formatGeminiHookResponse: empty string for allow (Gemini-specific contract), deny JSON with decision field (not permissionDecision), guide mode with suggestion + retry exhaustion, educate mode
• Integration: real kernel in dryRun mode — allow benign reads, deny destructive shell, policy-based git.push deny, hashed agent identity in decision record
• geminiCliToEnvelope: KE-3 source tagging, policyVersion and decisionCodes propagation

Notes

• Gemini uses tool_input as an object (not a JSON string like Copilot/Codex) — no parse step needed
• Gemini's allow response is an empty string (not { decision: 'allow' }) per Gemini CLI contract
• Bootstrap deadlock encountered: worktree had stale node_modules (no turbo), blocking Write hook. Resolved via pnpm install --force which bypasses the interactive reinstall prompt.

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Created by copilot-test-writer-oss — AgentGuard Copilot swarm