`registerProtocolDecl` resolved each method's param/return type NAME
through the flat, visibility-unaware `type_bridge.resolveAstType`, so a
type name colliding across modules bound to the wrong author. In the
repro the user's `Event` enum collides with the stdlib `event.Event`
struct (pulled in by `modules/std.sx`): the protocol grabbed the stdlib
struct, typed an inferred `g_plat.one_event()` as a fieldless struct,
bound the `case .key_up:(e)` payload to `.unresolved`, and emitted
"enum literal '.escape' has no destination type to resolve against".
Resolve both param and return types through
`resolveTypeInSource(pd.source_file, …)` — the visibility-aware resolver
pinned to the protocol's own declaring module, keeping the `Self → *void`
short-circuit. Brings the non-parameterized path to parity with
`instantiateParamProtocol` and concrete-fn signatures. No silent default:
not-visible / ambiguous names still diagnose and poison with `.unresolved`.
Closes issue 0132 — the protocol-return case left open by f13f4ab (which
fixed the enum/union/inline/error-set registration class). Regression
test: examples/0417-protocols-protocol-return-name-collision.sx.
- 0132: rewrite to the verified root cause -- protocol method signature
registration resolves type names via flat findByName and picks the wrong
same-name author. Original payload-field hypothesis kept as superseded;
repro switched to canonical `impl ... for` syntax. Still open (the
protocol path is unchanged).
- 0133: assigning a struct literal to a union member panics ("unresolved
type reached LLVM emission"); pre-existing, surfaced while testing.
- 0134: a same-name `error` set collapses into a namespaced import's set --
error-set declarations lack per-decl nominal identity (E6a gap); this is
what keeps the 0132-class error-ref resolution dormant.
