Audit of the class behind the planning bug: createFnAgent forwards no model
unless both defaultProvider and defaultModelId are set, after which
pi-coding-agent picks its own built-in default (anthropic/claude-opus-4-8).
Seven lanes resolved no pair at all, so they hit that path on every call --
a permanent 401 invalid x-api-key for custom-provider and subscription
operators, and a hole in test-mode forcing:
- milestone/slice interviews (no model plumbing at all)
- subtask breakdown, triage and streaming paths
- agent generation
- text refine and goal drafting
- agent reflection (optional ctor pair no production caller supplies)
Two more resolved the halves independently, which the runtime treats as
unset: research synthesis defaults and pr-conflict-resolver's hand-rolled
copy of resolveProjectDefaultModel (which also skipped test-mode overrides).
Add lane-session-model.ts as the shared resolver and a source ratchet that
fails when a dashboard session is constructed from an inline literal with no
model decision.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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