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/agents/builtin-agents/environment-context.ts

@@ -0,0 +1,8 @@
+import type { AgentConfig } from "@opencode-ai/sdk"
+import { createEnvContext } from "../env-context"
+
+export function applyEnvironmentContext(config: AgentConfig, directory?: string): AgentConfig {
+  if (!directory || !config.prompt) return config
+  const envContext = createEnvContext()
+  return { ...config, prompt: config.prompt + envContext }
+}