fix(coding-agent): returned ToolInfo[] from getAllTools extension API

The ExtensionAPI getAllTools() wired to session.getAllToolNames(),
returning bare tool-name strings. Upstream @earendil-works/pi-coding-agent
promises ToolInfo[] with sourceInfo, so extensions loaded through the
legacy-pi shim (e.g. gentle-pi) crashed on t.sourceInfo.source at every
session start.

Added SourceInfo/ToolInfo types plus SessionTools.getAllToolInfos(), which
returns { name, description, parameters, sourceInfo } and classifies each
tool as builtin/mcp/sdk/extension. Rewired every getAllTools action site
(interactive, acp, print/rpc, subagent executor) and the example extension.

Fixes #7732

packages/coding-agent/examples/extensions/tools.ts

@@ -36,7 +36,7 @@ export default function toolsExtension(pi: ExtensionAPI) {
 
 	// Find the last tools-config entry in the current branch
 	async function restoreFromBranch(ctx: ExtensionContext) {
-		allTools = pi.getAllTools();
+		allTools = pi.getAllTools().map(t => t.name);
 
 		// Get entries in current branch only
 		const branchEntries = ctx.sessionManager.getBranch();
@@ -66,7 +66,7 @@ export default function toolsExtension(pi: ExtensionAPI) {
 		description: "Enable/disable tools",
 		handler: async (_args, ctx) => {
 			// Refresh tool list
-			allTools = pi.getAllTools();
+			allTools = pi.getAllTools().map(t => t.name);
 
 			await ctx.ui.custom((tui, theme, _keybindings, done) => {
 				// Build settings items for each tool