refactor: wave 1 - extract leaf modules, rename catch-all files, split index.ts hooks

- Split 25+ index.ts files into hook.ts + extracted modules
- Rename all catch-all utils.ts/helpers.ts to domain-specific names
- Split src/tools/lsp/ into ~15 focused modules
- Split src/tools/delegate-task/ into ~18 focused modules
- Separate shared types from implementation
- 155 files changed, 60+ new files created
- All typecheck clean, 61 tests pass

src/shared/index.ts

@@ -16,6 +16,11 @@ export * from "./claude-config-dir"
 export * from "./jsonc-parser"
 export * from "./migration"
 export * from "./opencode-config-dir"
+export type {
+  OpenCodeBinaryType,
+  OpenCodeConfigDirOptions,
+  OpenCodeConfigPaths,
+} from "./opencode-config-dir-types"
 export * from "./opencode-version"
 export * from "./permission-compat"
 export * from "./external-plugin-detector"
@@ -28,12 +33,12 @@ export * from "./system-directive"
 export * from "./agent-tool-restrictions"
 export * from "./model-requirements"
 export * from "./model-resolver"
-export {
-  resolveModelPipeline,
-  type ModelResolutionRequest,
-  type ModelResolutionResult as ModelResolutionPipelineResult,
-  type ModelResolutionProvenance,
-} from "./model-resolution-pipeline"
+export { resolveModelPipeline } from "./model-resolution-pipeline"
+export type {
+  ModelResolutionRequest,
+  ModelResolutionProvenance,
+  ModelResolutionResult as ModelResolutionPipelineResult,
+} from "./model-resolution-types"
 export * from "./model-availability"
 export * from "./connected-providers-cache"
 export * from "./session-utils"