Converge Go-port parity seams: duplicated shim copies, vestigial exit-3 machinery, stale comments

[linhdmn]

The FR-GO-16 cutover left a dozen TODO-marked local shims that duplicate logic or pin contracts in comments — two sources of truth each:

• internal/orchestrator/autopr-merge.go:498-507 RunRemoteTaskSeam (SSH remote-task local copy; "replace with an internal/remote port when it lands" — no such package exists)
• internal/orchestrator/queue-bridge.go:91-105 defaultPlanner (verbatim TS fallbackPlan copy; TODO: delegate to the planner port)
• internal/workers/classify.go:5-7 retry-classification "minimal local port" (TODO: shared packages)
• internal/orchestrator/board-recovery.go:297-310 alert/notifier copies (TODO: internal/resilience port)
• internal/git/publish_seam.go:9-28 task-flow publish shim (TODO FR-GO-09 Go migration G1: integrations — Linear, Jira, GitHub, GitLab, webhooks, rate limits (FR-GO-09) #199; integrations.PushBranch/CreatePr now exist)
• internal/gates/regression.go:46-49 local WorktreeRunner; internal/orchestrator/merge.go:23-25 MergeRunner alias (TODO FR-GO-03 Go migration G1: git layer — worktrees, state branch, rebase-stack, doc-sync (FR-GO-03) #195)
• internal/scout/planner.go:17-23 local TicketSpec; internal/scout/prompt.go:596-599 ReadEvents/ComputeLessonScores subset (TODO FR-GO-04 Go migration G1: run logger + JSONL ledger + analytics (FR-GO-04) #197); internal/cli/state_glue.go:31, internal/cli/actions_status.go:549 queue/event copies
• Vestigial: internal/cli/root.go:28-29,504-547 exit-3 stub machinery registers nothing (all 51 commands wired) + internal/cli/stub_consistency_test.go; cmd/devagent/main.go:5-8 stale comment claims most commands exit 3
• Shallow-by-design stubs: internal/loopdriver/run.go:253 dry-run writes a literal "# dry-run stub" research file

Done when: each shim either converges onto the shared port or gets its TODO replaced by a durable contract comment; the exit-3 machinery and stale comments are removed; go vet ./... && go test ./... stays green.