refactor: remove the primary coding agent question and stored preference

[claude]

Requested by Justin Helmer · Slack thread

Before: setup asked "Which coding agent do you mainly use?" (or silently persisted a single detected agent), stored the answer as agent in ~/.polylane/config.json (also settable via POLYLANE_AGENT / config set --key agent), and that choice drove polylane map's agent pick and your-agent-first ordering in the integration connect picker.

After: setup never asks and never stores a preference. polylane map resolves its agent from the --agent flag, the only installed agent, or a map-time prompt — falling back to any runnable installed agent when non-interactive. The integration connect picker uses plain catalog order. Legacy agent fields in existing config files are silently ignored (no migration; the loader keeps tolerating unknown keys).

How: deleted settlePrimaryAgent/decidePrimaryAgent from src/commands/setup.ts and prioritizeCodeAgent from src/commands/integration/connect.ts; removed the agent field from Config/RawConfig, the loader's POLYLANE_AGENT ?? file.agent load, the config set/config show handling, and config.agent from map's precedence. isAgentId/validateAgentId in src/agents/registry.ts were left orphaned by this and removed too (map/setup --agent flags validate via agentById/the registry set as before). Tests: dropped the decidePrimaryAgent and prioritizeCodeAgent suites, and reworked test/loader.test.ts onto an isolated temp $HOME with a new test proving a config file carrying a legacy agent key still loads cleanly.

Validation: typecheck, lint, full test suite (317 pass / 0 fail), and build + smoke (config show, config set --key agent rejected with hint, setup dry-run, legacy-config load) all pass.

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[claude]

LGTM: clean removal of the primary-agent question/preference with no orphaned references or behavioral regressions found.

Verified against the checked-out head (f4f1221c, matches the PR API's head SHA):

• Diff read hunk-by-hunk across all 12 changed files (+37/-216, matching the PR's reported stats exactly).
• Reference sweep for every removed symbol — isAgentId, validateAgentId, prioritizeCodeAgent, decidePrimaryAgent, settlePrimaryAgent, PrimaryAgentDecision, config.agent/file.agent/POLYLANE_AGENT — grepped clean across src/ and test/. No dead imports, no orphaned exports. AGENT_IDS and typeOptionsForCategory remain in active use elsewhere (map.ts's own --agent validation, the category picker tests) so correctly left in place.
• PR body claims checked against code: the described deletions in setup.ts, integration/connect.ts, agents/registry.ts, config/loader.ts/schema.ts all match the diff; map's new precedence (flag > sole installed agent > interactive pick, no more config.agent in the chain) matches src/commands/map.ts:167-181; the picker in integration/connect.ts now uses plain catalog order with no initialValue/prioritizeCodeAgent call, matching the claim.
• Docs: README, AGENTS.md, ERRORS.md have no stale mentions of the removed agent config key or config set --key agent.
• Local checks (npm ci, npm run codegen — live spec fetch to api.polylane.com succeeded, npm run typecheck, npm run lint, npm run test): all clean. Test suite: 317 pass / 0 fail / 72 suites, matching the PR body's reported count exactly. New test/loader.test.ts case for a legacy agent key in the config file passes and correctly asserts it's dropped (!('agent' in config)).
• CI via GitHub API: all 3 check runs green — checks / Test & typecheck on Node 20.x, 22.x, and 24.x, all completed/success.
• Backward compat: legacy agent field in an existing ~/.polylane/config.json is silently tolerated (loader ignores unknown keys; no throw), consistent with the "no migration" claim — verified by the new loader test and by inspection of writeConfigFile's merge behavior (a stray legacy key just rides along untouched, never surfaced).

Nit (non-blocking): map --agent's help text now reads "defaults to an installed agent," which slightly undersells the interactive-pick fallback when multiple agents are installed — could say "an installed agent, or a prompt when more than one is found" for precision, but this is cosmetic only.

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Generated by Claude Code

[github-actions]

Auto-approved: Claude reviewed this PR and posted an LGTM verdict (see its review). A repo admin enabled this via the auto-approve workflow.

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Generated by Claude Code