#3347 feat: compile-check learns which names a public API change touches

Summary

• When an assembly's public API changes, compile-check now learns which names the change touches (type and member names), or that no name can tell it. This is the groundwork for compiling only the dependents that write one of those names.
• No scheduling change; the next PR consults the names. Which dependents compile is the same as before.

User Impact

None yet. The VibeLog (ULOOP_DEBUG) surface_checks entries now show changed_name_count, the first 10 changed_names, and unnamed (why no name tells the change), so the next PR's effect can be measured on a real project.

Changes

• Worker (C#):
  • Every row of a surface description now carries the type and member it belongs to and a row kind. The same / different answer still comes from comparing the texts in order, so it does not change.
  • On "different", the worker collects names from the rows whose text one side holds more often than the other (rows that only moved are not a named change).
  • A change a dependent can feel without writing any name is unnamed and carries no names:
    • a manifest row;
    • for a type both sides have: its flags or attributes, base type, interfaces, type parameters, an instance field of a value type, a parameterless constructor, an indexer;
    • an abstract member added;
    • an operator, a compiler-generated member, or a member C# binds by pattern (GetEnumerator, GetAwaiter, Add, Deconstruct, SetResult, …);
    • every row of an interpolated string handler or collection builder type;
    • every row of a type in System, System.*, Microsoft.CodeAnalysis or Microsoft.CodeAnalysis.*, on one side or both. The compiler looks these up by name (IsExternalInit for init, Index for ^1), so a dependent uses them without writing their names. Only polyfills live there in a project. A project that puts its own extension classes in System.* gets every dependent compiled when one of their members changes; the docs and the ADR in the follow-up PRs say so;
    • more than 2000 names.
  • A type added or removed is named by its type name (and its members). Namespace segments are named only when one side lacks that namespace.
  • A member whose name starts with an accessor prefix names itself and the name without the prefix (get_P and P, also for an explicit implementation N.IFoo.get_P). Only its metadata tells an accessor from a method declared as get_Value, which a dependent writes with the prefix.
  • The base type moves from the type row to a row of its own, so the description version goes from sv1 to sv2. No other row's text changes.
• Go:
  • The response, the surface record (format version 1 → 2, so an old record is asked again once), and SurfaceVerdict carry ChangedNames / UnnamedReason.
  • A different answer that names nothing reads as unnamed, both in the client and where an answer becomes a verdict.
  • Only a verdict that is not kept, has names, and has no unnamed reason is a named change. Every other verdict, including the zero verdict of a failed unit, still affects every dependent.
• docs/vibe-logs.md documents the new surface_checks fields.

Verification

• C# (tests/CompileCheckWorker.UnitTests): 113 tests pass.

  • AssertDifferent now also checks the answer against the dependent it compiles: the change is unnamed, or the dependent writes one of its names. All existing different-surface cases pass this check.
  • New tests use dependents that never write the changed type's name (foreach, await, operators, new() and unmanaged constraints, casts, boxing, a renamed indexer, an extension GetAwaiter).
  • One limitation: adding an interface member with a default body cannot be emitted against the fixture's .NET Standard 2.0 (CS8701). That rule is tested by building the description rows directly.

• Mutations, each tried on the worker and then restored:

  Mutation	Fails
  Empty the pattern-bound member list	foreach / await on an unnamed type, extension GetAwaiter, GetEnumerator added, SetResult changed
  Treat type-shape rows as members	base type changed, interface added
  Treat every type as one-sided	21 tests, including abstract / sealed / ref struct
  Always name namespace segments	nested generic member, new namespace
  Value-type instance field as member	struct field added
  Parameterless constructor as member	parameterless constructor removed
  Indexer as member	indexer added, renamed indexer changed
  Drop the well-known namespace check	well-known type removed (init), well-known type member changed (^1)
  Do not keep the name before the accessor prefix	method named like an accessor, explicit accessor implementation, and 4 tests whose expected names include accessors
  Go: a different answer without names reads as named	TestVerdictFromWorkerTreatsADifferenceWithoutNamesAsUnnamed
  Go: record format version stays 1	TestReusableSurfaceVerdictRejectsAVersionOneRecord

• In cli/dispatcher:

  • go test -race -count=1 ./internal/compilecheck/... ./internal/dispatcher/... passes.

• In each of the four Go modules:

  • gofmt -l is empty;
  • go vet passes;
  • golangci-lint run reports 0 issues.

• go test ./... passes in cli/dispatcher and cli/release-automation, including ./internal/architecture/.... In cli/common and cli/project-runner, one test each fails only because the local sandbox refuses a directory under /tmp and a Unix socket bind; neither module is touched here.

• scripts/check-code-complexity.sh and scripts/check-file-length.sh pass.