fix(tbtc): wire reservation actions into the coordination checklist

[piotr-roslaniec]

Summary

Blocker gap, found while preparing PR (M3 multi-signer integration test),
not while doing the ask. Adds docs/spec/reservations/m1-keep-core-readiness/01-gap-analysis.md
Blocker row 2: pkg/tbtc/coordination.go's getActionsChecklist never included
ActionReservationAnchor/ActionReservationReanchor, so the reservation
acceptance and re-anchor proposal tasks were structurally unreachable by the
live coordination loop regardless of #4276/#4277 landing.

Stacked on m1/reservation-protobuf-marshaling (#4277),
tip 72373fcad.

The gap

pkg/tbtcpg.ProposalGenerator.Generate only runs a task if its ActionType()
appears in request.ActionsChecklist (tbtcpg.go:124-135) - it never
iterates pg.tasks directly. That checklist comes from exactly one place:
coordinationExecutor.getActionsChecklist in pkg/tbtc/coordination.go.
That function builds the list from scratch every call and never mentioned
reservations. NewReservationAcceptanceTask/NewReservationReanchorTask
were registered into pg.tasks whenever config.Reservations.Enabled=true
(tbtcpg.go:88-92), but with no matching checklist entry, Generate's
per-window loop never selected them - both tasks were dead code in
production.

Every existing unit test for these tasks (reservation_acceptance_test.go,
reservation_reanchor_test.go) calls task.Run(request) directly, bypassing
getActionsChecklist/Generate entirely - which is exactly why no prior
PR's test suite caught this. It only became visible while building the
real multi-signer coordination-round test the M1 plan's Milestone 3 calls
for, which is the first test in this repo to exercise the actual production
call path (coordinationExecutor.coordinate -> getActionsChecklist ->
ProposalGenerator.Generate) for these action types.

Fix

ActionReservationAnchor/ActionReservationReanchor are now appended
unconditionally in getActionsChecklist, checked on every coordination
window - like ActionRedemption, not frequency-gated like
DepositSweep/MovedFundsSweep/MovingFunds - since both are custody-critical
(an unaccepted reservation or a stale re-anchor risks reservation stranding,
not just reduced throughput).

A node with reservations disabled is unaffected: Generate already treats a
checklist action with no matching registered task as "unsupported" and skips
it without error (tbtcpg.go:131-135) - the same mechanism every other
optional per-node task already relies on. No new config plumbing needed in
pkg/tbtc.

Testing

• Updated TestCoordinationExecutor_GetActionsChecklist and its
  _PostActivation sibling: every non-nil expected checklist now includes
  both new actions right after ActionRedemption. Extended
  assertChecklistOrdering's priority map (Redemption=0, ReservationAnchor=1, ReservationReanchor=2, existing priorities shifted).
• Added TestCoordinationExecutor_GetActionsChecklist_ReservationActionsAlwaysPresent,
  a dedicated regression guard (pre/post-activation x 4th/non-4th window)
  decoupled from the large table-driven test.
• go test ./pkg/tbtc/... ./pkg/tbtcpg/...: 476/476 pass.
• go build ./... && go test ./...: full repo, 49 packages, zero FAIL.
• gofmt -l / go vet: clean on both changed files.

Not in this PR

• Milestone 2 test-coverage backfill and the M3 multi-signer integration
  test itself - both tracked as separate follow-up PRs; the M3 test will be
  built on top of this branch now that the path it needs to exercise is
  actually reachable.

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}