Clear all `barrel/index-no-impl` violations in src/main (14 barrels) by
turning each index.ts into a pure re-export or dissolving it:
- Aggregation buckets → drop the barrel, move the assembled object/array/fn
to a named file, deep-import at the sole consumer: data/api/handlers →
apiHandlers.ts, ipc/handlers → ipcHandlers.ts, migrators → migratorRegistry.ts,
params/features → internalFeatures.ts, browser/tools → registry.ts,
builtin → registerBuiltinTools.ts, db/seeding → seederRegistry.ts.
- Single-impl dirs flattened: provider/extensions.ts, provider/cherryai.ts.
- Barrel kept, impl extracted to a named file: i18n/resolver.ts,
ai/types/providerConfig.ts.
- Route subdir flattened to match its flat siblings: routes/knowledge.ts +
routes/knowledgeSchemas.ts.
- runtime: replace the import-time `claudeCode/register` side effect with an
explicit registerRuntimeDrivers() invoked from AgentSessionRuntimeService.onInit,
so runtime/index.ts stays a pure re-export.
- loop: dissolve the non-enforced barrel into loop/types.ts + loop/hookRunner.ts.
Also route DataApiService's apiHandlers import through the data/api barrel,
and expose ClaudeCodeRuntimeDriver via the claudeCode barrel, clearing the two
deep-import warnings this batch touched. Docs and comments updated to the new paths.
