feat(FN-3332): add droid runtime plugin with event bridge and process manag

The merge delivers a new `fusion-plugin-droid-runtime` plugin providing a full MCP server and runtime adapter for droid-based agents, with event bridging, process management, tool mapping, and a prompt builder. It also adds agent delegation and org hierarchy tools to the pi extension, while fixing a

Fusion-Task-Id: FN-3332

plugins/fusion-plugin-droid-runtime/src/tool-mapping.ts

@@ -0,0 +1,147 @@
+/**
+ * Single-source-of-truth tool mapping table for bidirectional translation
+ * between Droid CLI tool names/arguments and pi tool names/arguments.
+ *
+ * All lookup tables are derived from the TOOL_MAPPINGS array.
+ * Unknown tools and arguments pass through unchanged.
+ */
+
+/**
+ * A mapping entry for a single tool.
+ * `args` maps Claude argument names to pi argument names (only renamed args).
+ */
+export interface ToolMapping {
+  claude: string;
+  pi: string;
+  args: Record<string, string>;
+}
+
+/**
+ * The canonical tool mapping table. All other lookup structures are derived from this.
+ */
+export const TOOL_MAPPINGS: ToolMapping[] = [
+  { claude: "Read", pi: "read", args: { file_path: "path" } },
+  { claude: "Write", pi: "write", args: { file_path: "path" } },
+  {
+    claude: "Edit",
+    pi: "edit",
+    args: { file_path: "path", old_string: "oldText", new_string: "newText" },
+  },
+  { claude: "Bash", pi: "bash", args: {} },
+  { claude: "Grep", pi: "grep", args: { head_limit: "limit" } },
+  { claude: "Glob", pi: "find", args: {} },
+];
+
+/** Prefix for custom pi tools exposed via MCP. */
+export const CUSTOM_TOOLS_MCP_PREFIX = "mcp__custom-tools__";
+
+/** Set of built-in pi tool names derived from TOOL_MAPPINGS for O(1) lookup. */
+const BUILT_IN_PI_NAMES = new Set(TOOL_MAPPINGS.map((m) => m.pi));
+
+/**
+ * Check if a pi tool name is a custom tool (not one of the 6 built-in tools).
+ * Used by prompt builder to decide whether to add MCP prefix in history replay.
+ */
+export function isCustomToolName(piName: string): boolean {
+  return !BUILT_IN_PI_NAMES.has(piName);
+}
+
+/**
+ * Check if a Claude tool name maps to a pi-known tool.
+ * Returns true for built-in tools (Read, Write, etc.) and custom MCP tools (mcp__custom-tools__*).
+ * Returns false for internal Claude Code tools (ToolSearch, Task, Agent, etc.) that pi cannot execute.
+ * Used by event bridge to filter out internal tool calls.
+ */
+export function isPiKnownDroidTool(claudeName: string): boolean {
+  if (claudeName.startsWith(CUSTOM_TOOLS_MCP_PREFIX)) return true;
+  return claudeName.toLowerCase() in DROID_TO_PI_NAME;
+}
+
+// Derived lookup maps
+
+/** Lowercase Claude name -> pi name */
+const DROID_TO_PI_NAME: Record<string, string> = {};
+/** Pi name -> PascalCase Claude name */
+const PI_TO_DROID_NAME: Record<string, string> = {};
+/** Lowercase Claude name -> { claudeArgName: piArgName } */
+const DROID_TO_PI_ARGS: Record<string, Record<string, string>> = {};
+/** Pi name -> { piArgName: claudeArgName } */
+const PI_TO_DROID_ARGS: Record<string, Record<string, string>> = {};
+
+for (const m of TOOL_MAPPINGS) {
+  DROID_TO_PI_NAME[m.claude.toLowerCase()] = m.pi;
+  PI_TO_DROID_NAME[m.pi] = m.claude;
+  DROID_TO_PI_ARGS[m.claude.toLowerCase()] = m.args;
+
+  // Build reverse arg map
+  const reverseArgs: Record<string, string> = {};
+  for (const [from, to] of Object.entries(m.args)) {
+    reverseArgs[to] = from;
+  }
+  PI_TO_DROID_ARGS[m.pi] = reverseArgs;
+}
+
+// Handle glob/find asymmetry: pi's "glob" also maps back to Claude's "Glob"
+PI_TO_DROID_NAME["glob"] = "Glob";
+
+/**
+ * Map a Claude tool name to the corresponding pi tool name.
+ * Strips the mcp__custom-tools__ prefix for custom tools first,
+ * then falls back to case-insensitive built-in lookup.
+ * Unknown tool names pass through unchanged.
+ */
+export function mapDroidToolNameToPi(claudeName: string): string {
+  // Strip custom-tools MCP prefix first (e.g., "mcp__custom-tools__deploy" -> "deploy")
+  if (claudeName.startsWith(CUSTOM_TOOLS_MCP_PREFIX)) {
+    return claudeName.slice(CUSTOM_TOOLS_MCP_PREFIX.length);
+  }
+  // Standard built-in tool mapping (case-insensitive)
+  return DROID_TO_PI_NAME[claudeName.toLowerCase()] ?? claudeName;
+}
+
+/**
+ * Map a pi tool name to the corresponding Claude tool name.
+ * Direct lookup. Unknown tool names pass through unchanged.
+ */
+export function mapPiToolNameToDroid(piName: string): string {
+  return PI_TO_DROID_NAME[piName] ?? piName;
+}
+
+/**
+ * Translate Claude tool arguments to pi format.
+ * Only known renamed arguments are translated; all others pass through unchanged.
+ * This prevents dropping unknown/extra arguments (Pitfall 5).
+ */
+export function translateDroidArgsToPi(
+  claudeToolName: string,
+  args: Record<string, unknown>,
+): Record<string, unknown> {
+  const renames = DROID_TO_PI_ARGS[claudeToolName.toLowerCase()];
+  if (!renames || Object.keys(renames).length === 0) return args;
+
+  const result: Record<string, unknown> = {};
+  for (const [key, value] of Object.entries(args)) {
+    const newKey = renames[key] ?? key;
+    result[newKey] = value;
+  }
+  return result;
+}
+
+/**
+ * Translate pi tool arguments to Claude format.
+ * Only known renamed arguments are translated; all others pass through unchanged.
+ */
+export function translatePiArgsToDroid(
+  piToolName: string,
+  args: Record<string, unknown>,
+): Record<string, unknown> {
+  const renames = PI_TO_DROID_ARGS[piToolName];
+  if (!renames || Object.keys(renames).length === 0) return args;
+
+  const result: Record<string, unknown> = {};
+  for (const [key, value] of Object.entries(args)) {
+    const newKey = renames[key] ?? key;
+    result[newKey] = value;
+  }
+  return result;
+}