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/tools/lsp/find-references-tool.ts

@@ -0,0 +1,43 @@
+import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
+
+import { DEFAULT_MAX_REFERENCES } from "./constants"
+import { formatLocation } from "./lsp-formatters"
+import { withLspClient } from "./lsp-client-wrapper"
+import type { Location } from "./types"
+
+export const lsp_find_references: ToolDefinition = tool({
+  description: "Find ALL usages/references of a symbol across the entire workspace.",
+  args: {
+    filePath: tool.schema.string(),
+    line: tool.schema.number().min(1).describe("1-based"),
+    character: tool.schema.number().min(0).describe("0-based"),
+    includeDeclaration: tool.schema.boolean().optional().describe("Include the declaration itself"),
+  },
+  execute: async (args, context) => {
+    try {
+      const result = await withLspClient(args.filePath, async (client) => {
+        return (await client.references(args.filePath, args.line, args.character, args.includeDeclaration ?? true)) as
+          | Location[]
+          | null
+      })
+
+      if (!result || result.length === 0) {
+        const output = "No references found"
+        return output
+      }
+
+      const total = result.length
+      const truncated = total > DEFAULT_MAX_REFERENCES
+      const limited = truncated ? result.slice(0, DEFAULT_MAX_REFERENCES) : result
+      const lines = limited.map(formatLocation)
+      if (truncated) {
+        lines.unshift(`Found ${total} references (showing first ${DEFAULT_MAX_REFERENCES}):`)
+      }
+      const output = lines.join("\n")
+      return output
+    } catch (e) {
+      const output = `Error: ${e instanceof Error ? e.message : String(e)}`
+      return output
+    }
+  },
+})