[schickling-assistant]

Problem

#3642 introduced st fleet transports add fabric --prefer, but restoring Tailscale-first automatic routing required editing fleet.toml by hand.

Goal

st fleet transports prefer <tailscale|fabric> [--no-service] restores either enabled carrier's priority without changing exposure or enablement.

Decisions

• Reorder only, preserving every other carrier's relative order. Reject a carrier that is not enabled; already-first is a no-op.
• Reuse the fleet settings lock, atomic 0600 saver, endpoint publication and daemon/worker restart guidance.
• No Fabric executable calls on the preference path.

Verification

Added integration coverage for both directions, disabled-carrier refusal, unchanged exposure tool calls and endpoint membership, no-op inode preservation, actual settings-lock contention and reloading under lock, atomic inode replacement with intact old contents, and 0600 permissions. Extended conflicting-service setup coverage to the new command.

• Initial Workspace CI passed build, clippy, fleet compatibility and isolation, but caught missing action coverage and actor-contract inventory updates. Those inventories are now complete.
• The entire actor-contract snapshot was regenerated from the generator's actual value emitted in that hosted assertion, mechanically decoding Rust debug wrappers rather than hand-merging classifications.
• Corrected-inventory Workspace CI passed 8,773 tests, build, clippy and the aggregate gate. The existing daily-only fleet filter excluded the new tests; the filter now keeps both preference command contracts on the PR lane.
• Final-head Workspace CI is green at 3448c8cd9a9353bbc513d364c599794d74553afb: 8,775 tests passed across both shards, zero flaky; build, clippy, fleet compatibility, freshness, isolation, web and TypeScript jobs passed.
• Both new acceptance tests executed and passed: disabled-carrier refusal and bidirectional reorder, lock, atomic save, no-op and unchanged exposure.
• Independent internal correctness GO at the exact head.

Before: restoring Tailscale priority required hand-editing fleet.toml.
After: st fleet transports prefer tailscale performs the locked reorder and refreshes services (or gives both restart commands with --no-service).

Commit used ST_SKIP_EVIDENCE=1 because hosted CI, rather than local build evidence, is required for this task.

Complexity

No new dependencies or abstraction; one CLI variant uses the existing transport mutation path.

Concerns

Explicit peer URLs still override automatic carrier preference, and loopback remains the last automatic fallback. Preference is local to each member.

Friction & bottlenecks

A read-only GitHub log request was incorrectly refused by the subprocess runner; the ordinary shell path worked without changing authentication. Feedback was filed. No measured resource bottleneck.

Follow-ups

None.

References

Refs #3642. Symmetric rollback for Fabric-first routing.

Posted on behalf of @schickling

field	value
agent_identity	agent/dotfiles/fabric-mesh
session	01a1ecd5
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.9.1
agent_runtime	OMP 18.9.1
agent_model	anthropic/claude-opus-5-5
worktree	fractal/2026-10-23-fleet-transport-prefer

[schickling-assistant]

Independent internal correctness GO at exact head 48a4ceb from reviewer PreferCorrectness. Static review covered all changed Rust commands, tests, docs and release note, command dispatch, endpoint publication, atomic saving, settings-lock fencing and transport-order consumers. No blocking findings (confidence 0.91). Reviewer confirmed reordering preserves enablement and other carrier order; disabled carriers are refused; already-first avoids writes/publication/restarts; exposure tools are never invoked. This is code-review evidence, not executed-test evidence. Hosted Workspace CI proof is running separately: https://github.com/compoundingtech/fractal/actions/runs/39882107450 .

Posted on behalf of @schickling

field	value
agent_identity	agent/dotfiles/fabric-mesh
session	01a1ecd5
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.9.1
agent_runtime	OMP 18.9.1
agent_model	anthropic/claude-opus-5-5
worktree	smalltalk/main

[schickling-assistant]

Renewed independent internal correctness GO at exact head f845384 from reviewer PreferCorrectness (confidence 0.93). Static review of the four-file documentation-only delta found no blocking defects: coverage rows reference the reviewed tests, the actor-contract entry matches the clap-derived no-actor classification and neighboring transport commands, and transport docs accurately describe ordering and guards. Prior Rust review remains applicable. No local checks were run. Corrected-head hosted proof: https://github.com/compoundingtech/fractal/actions/runs/39885649120 .

Posted on behalf of @schickling

field	value
agent_identity	agent/dotfiles/fabric-mesh
session	01a1ecd5
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.9.1
agent_runtime	OMP 18.9.1
agent_model	anthropic/claude-opus-5-5
worktree	fractal/2026-10-23-fleet-transport-prefer

[schickling-assistant]

Final renewed independent internal correctness GO at exact head 3448c8c from reviewer PreferCorrectness (confidence 0.95). The sole new delta exempts both fleet::transport_prefer_ tests from the daily-only exclusion, retaining these command contracts in PR CI while preserving other fleet exclusions. Prior Rust and documentation review conclusions remain applicable. This is a static review GO, not a test execution claim. Final-head hosted proof: https://github.com/compoundingtech/fractal/actions/runs/39888802518 .

Posted on behalf of @schickling

field	value
agent_identity	agent/dotfiles/fabric-mesh
session	01a1ecd5
agent_persona	generalist
agent_supervisor	unavailable
agent_tool	OMP
agent_tool_version	18.9.1
agent_runtime	OMP 18.9.1
agent_model	anthropic/claude-opus-5-5
worktree	smalltalk/main

[myobie]

Intake A FINAL GO #3677 (feat(fleet): prefer either enabled replication transport) at exact head 3448c8c (3 commits 48a4ceb, f845384, 3448c8c; not draft; behind main 0, CLEAN).

Read the source diff (fleet_cli.rs, main.rs, setup.rs, daily-only.filterset, action-coverage.json, actor-contract.json, release note). st fleet transports prefer <tailscale|fabric> [--no-service] refuses a carrier that is not enabled, is a no-op (no restart, no save) when already first, otherwise rotates only that entry to the front (transports[..=index].rotate_right(1)), keeping the others in relative order, then uses the existing locked saver and endpoint publication. No exposure/Fabric executable calls on this path, no wire, schema or store change, no store.rs. The filterset keeps fleet::transport_prefer_ on the PR lane; the actor-contract and action-coverage rows are added (actor none).
CI on this head: workspace runs green, all required checks success, both linux-tests shards nextest flaky 0, no TRY/FLAKY. By name in the final run: fleet::transport_prefer_reorders_under_lock_without_changing_exposure, fleet::transport_prefer_refuses_disabled_carriers_without_saving, setup::uninstall_and_fleet_conflicts_precede_settings_mutations, action_coverage::action_inventory_matches_contract_and_has_existing_test_references and the actor_contract tests all PASS. The earlier inventory red the PR describes was a real defect found by CI and fixed, not a retry.
Direction is the q33 decision Johannes already made (follow-up to #3642, same feature); the change is an additive CLI command, so it queues normally (not alone). Not covered: --no-service restart path, which I did not run. A head change voids this.