refactor(tests+frontend): one http_sink helper for the hook tests; apiErrorMessage replaces ten hand-rolled error-body parses; type X, import specifiers are not definitions (#2904, milestone 299 step 6)

tests/helpers.http_sink replaces three module-local _Sink handlers (the
write-path tests and the after-write test). ProjectView + SettingsView
parsed `(e as {body?:{error?}}).body?.error || fallback` by hand ten times
beside the apiErrorMessage canon (#2853) - all ten now call it. The
extractor (server + the hook awk mirror) no longer reads `import { type Foo }`
as a definition of Foo - that was the last "identical body" sym family.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

plugin/hooks/scribe_defs.sh

@@ -58,6 +58,13 @@ scribe_defs() {
       if (match(line, /^(function|def|class|func|fun|fn|sub|struct|trait|interface|enum|object|protocol|type)[[:space:]]+[A-Za-z_$]/)) {
         t = line; sub(/^[a-z]+[[:space:]]+/, "", t)
         sub(/[^A-Za-z0-9_$].*$/, "", t)
+        # `type` defines only when something follows the name (= or {); an
+        # import specifier `type Foo,` is the same two words and defines
+        # nothing (mirror of coverage.py, #2904).
+        if (line ~ /^type[[:space:]]/) {
+          rest = line; sub(/^type[[:space:]]+[A-Za-z_$][A-Za-z0-9_$]*/, "", rest)
+          if (rest !~ /[={]/) next
+        }
         if (t != "" && t !~ /^__.*__$/) print "sym\t" t; next
       }
       # Arrow/expression assignment: const name = (…) / let name = async (