Configurable default dispatch agent (unassigned → codex, not claude) — Task 207

[e-fu]

Problem

An unassigned roadmap task dispatched via the default `recommend` adapter hits `CapabilityScore.recommend` with no measured scores and falls back to the hardcoded `@fallback_agent :claude` (`capability_score.ex:51`) — silently spending precious Claude tokens. Agents also frequently omit `assignee` at task creation, so this path is common.

Fix (configurable, by layer)

• `Harness.Config` — new `{:dispatch, :default_agent}` key, default `:codex`, `ui_editable?`, new `:agent` validator (membership in the implementer set `[:claude,:codex,:cursor,:grok,:antigravity,:pi]`).
• `CapabilityScore.fallback_recommendation` — reads `Config.get({:dispatch, :default_agent})` instead of the hardcoded `:claude`. An explicit `:fallback_agent` opt still wins.
• `SettingsLive` — dedicated Dispatch default `` card + `set_default_agent` handler; the `:agent` entry is excluded from the number-input config card. Reviewer axis untouched — Claude stays reviewer-eligible (`set_reviewer_eligible`). Implementer default cheap, reviewer Claude-allowed. Root cause — the `rmap.md` include (separate global edit) now pushes `assignee` at creation so agents stop omitting it; the default is the safety net. Tests 62 green across `config_test`, `capability_score_test`, `settings_live_test`: `:agent` validation (accept in-set, reject `:droid`/`:human`), schema default is `:codex`, fallback reads the configured default, and the dashboard card persists / rejects. Deliberately not changed: `rmap resolve_target` (the interactive CLI error is correct), reviewer-eligibility, no new adapter.

[e-fu]

Merged directly to development (3c22a81) — PR not needed.

[Copilot]

Pull request overview

This PR makes the “no capability-score data” fallback implementer agent configurable (defaulting to :codex) so unassigned tasks don’t silently route to :claude and consume higher-cost tokens. It introduces a new Harness.Config key for the default dispatch agent and exposes it in the dashboard settings UI, while keeping reviewer eligibility behavior unchanged.

Changes:

• Add {:dispatch, :default_agent} as a :agent-typed config entry (default :codex) with validation against a closed implementer set.
• Update CapabilityScore’s no-data fallback to use the configured default dispatch agent unless an explicit :fallback_agent opt is provided.
• Add a dedicated “Dispatch default” settings card + event handler and extend test coverage for config validation, UI persistence, and fallback behavior.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/harness/config/entry.ex	Extends config value types to include :agent.
lib/harness/config.ex	Adds dispatch default agent schema entry, closed implementer set, and validation.
lib/harness/capability_score.ex	Switches fallback agent from hardcoded to config-driven default.
lib/harness/dashboard/settings_live.ex	Adds dashboard UI + handler for setting the default dispatch agent; excludes :agent from numeric config editor.
test/harness/config_test.exs	Adds validation and defaulting tests for :agent-typed dispatch default.
test/harness/capability_score_test.exs	Verifies fallback uses configured dispatch default when no :fallback_agent is provided.
test/harness/dashboard/settings_live_test.exs	Verifies UI renders the card, persists selection, and rejects unknown agent values.

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Wire dispatch default into cron poller

This only updates the no-data CapabilityScore.recommend fallback; autonomous roadmap polling does not go through this path. I checked lib/harness/cron/roadmap_poller.ex, where task_agent/1 still maps a missing assignee to the module attribute @default_agent :claude, so an rmap ready task with assignee: nil will still enqueue Claude regardless of the new setting/UI. Please route that missing-assignee branch through Config.get({:dispatch, :default_agent}) too, or share one helper, so the setting actually protects cron-dispatched unassigned work.

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