[ndeloof]

What this PR does, in one sentence

Rewrites the comments of pkg/compose that still describe the imperative start path deleted by the migration of compose start to the plan engine, without touching a line of code.

Context

startService and startServiceContainer are gone since compose start runs on a start-only plan (#14296). About fifty comments, in the reconciler, the executor, start/up and their tests, still cite them — or isNotRunning, or a start "walked by InDependencyOrder" — as the source of a behavior the plan now owns. A reader looking for those functions finds nothing, and a few comments say which commands still walk the dependency order, which is no longer true (only restart, stop, down and the classic build do).

What the PR brings

• The comments state the behavior itself instead of pointing at deleted code, keeping the rationale (why a scale-0 service is still visited, why compose start stays silent on a no-op, why the wait timeout applies without --wait, …) and dropping the migration history (review-finding anecdotes, "the old engine").
• The header of service_containers.go and a few helper comments now name the commands that really still use the dependency order.
• The comment of startMx now ties the mutex to [BUG] docker engine and desktop expose random ports differently #12846 and states that Engine 28.3.0 fixed the cause (Avoid selecting duplicate host ports for mappings to 0.0.0.0 and specific addresses moby/moby#50054), so that it can be found and removed once Engine 28.x is out of support. It also says which start paths take it: the plan executor's only, not restart, run, the relay or the hook runners, which the previous wording claimed.
• Nothing else: no code, no directive (//go:, //nolint), no test changed. Four commits — production comments, test comments, a rewrap that follows their review, and the startMx annotation — so each reads on its own.

Why this is no functional change

• Every added or removed line of the diff is a // comment line.
• The token stream of each of the 394 Go files of pkg/, cmd/ and internal/, comments excluded, is identical before and after (a control mutation of one return is detected by the same check).
• Binaries built from main and from this branch have the same symbols, sizes and types; only the line tables (runtime.pclntab, runtime.epclntab) and the VCS stamp of the build info differ, as expected when comment lines move.
• go vet, gofmt and the linter are unchanged (only the known findings), and go test ./pkg/... -race passes except pkg/watch, which fails the same way on main.
• The standalone e2e suite, run with the same environment on both binaries: 332 results each, no difference at all (318 pass, 3 skipped, and the same 11 failures on both sides: the provider scenarios cannot find example-provider in the PATH, and TestComposeModel).

Part of #14081 (Lot 3). The other half of the lot — moving the dependency-wait helpers out of service_containers.go — follows #14385, which rewrites waitDependencyReached.

🤖 Generated with Claude Code

[docker-agent]

Assessment: 🟢 APPROVE

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pkg/compose/service_containers.go	66.66%	2 Missing ⚠️

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