feat(navigation): add symbol index and LSP navigation features

The changes introduce a Tcl symbol index powering LSP navigation
features across the workspace. A navigation API exposes
snapshots and update hooks, enabling goto-definition,
references, and rename using the index. Background indexing
now watches Tcl files and rebuilds the index to stay in sync.

- Add Tcl symbol index and navigation snapshot API
- Wire go-to-definition, references, and rename using the index
- Watch Tcl files and refresh the index in the background

client/src/common/handlers.ts

@@ -137,6 +137,102 @@ export function hoverCdlHandler(document: vscode.TextDocument, position: vscode.
     return undefined
 }
 
+function escapeRegExp(value: string): string {
+    return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&")
+}
+
+export function cdlEventAtPosition(
+    document: vscode.TextDocument,
+    position: vscode.Position
+): string | undefined {
+    const line = document.lineAt(position.line).text
+    const match = /^\s*EVENT\s+([^\s{]+)/.exec(line)
+    if (!match) {
+        return undefined
+    }
+
+    const declarationStart = match.index
+    const eventEnd = line.indexOf(match[1], match.index) + match[1].length
+    if (position.character < declarationStart || position.character > eventEnd) {
+        return undefined
+    }
+    return match[1]
+}
+
+export async function definitionCdlEventHandler(
+    document: vscode.TextDocument,
+    position: vscode.Position,
+    token: vscode.CancellationToken
+): Promise<vscode.Location[] | undefined> {
+    const eventName = cdlEventAtPosition(document, position)
+    if (!eventName) {
+        return undefined
+    }
+
+    const handlerName = `MOM_${eventName}`
+    try {
+        const symbols = await vscode.commands.executeCommand<vscode.SymbolInformation[]>(
+            "vscode.executeWorkspaceSymbolProvider",
+            handlerName
+        )
+        const indexedLocations = (symbols || [])
+            .filter(
+                (symbol) =>
+                    symbol.kind === vscode.SymbolKind.Function &&
+                    (symbol.name === handlerName ||
+                        symbol.name.endsWith(`::${handlerName}`))
+            )
+            .map((symbol) => symbol.location)
+        if (indexedLocations.length > 0) {
+            return indexedLocations
+        }
+    } catch {
+        // The Tcl language server may still be starting; use the file fallback below.
+    }
+
+    const declaration = new RegExp(
+        `^\\s*proc\\s+(?:::)?${escapeRegExp(handlerName)}(?=\\s|\\{)`
+    )
+    const tclFiles = await vscode.workspace.findFiles(
+        "**/*.tcl",
+        "**/{.git,.nox,.venv,dist,node_modules,out}/**"
+    )
+    const locations: vscode.Location[] = []
+
+    for (const uri of tclFiles) {
+        if (token.isCancellationRequested) {
+            return undefined
+        }
+        let tclDocument: vscode.TextDocument
+        try {
+            tclDocument = await vscode.workspace.openTextDocument(uri)
+        } catch {
+            continue
+        }
+        for (let lineNumber = 0; lineNumber < tclDocument.lineCount; lineNumber++) {
+            const line = tclDocument.lineAt(lineNumber).text
+            const match = declaration.exec(line)
+            if (!match) {
+                continue
+            }
+            const start = line.indexOf(handlerName, match.index)
+            locations.push(
+                new vscode.Location(
+                    uri,
+                    new vscode.Range(
+                        lineNumber,
+                        start,
+                        lineNumber,
+                        start + handlerName.length
+                    )
+                )
+            )
+        }
+    }
+
+    return locations.length > 0 ? locations : undefined
+}
+
 export function tclDocumentSymbolProvider(document: vscode.TextDocument): vscode.DocumentSymbol[] {
     const symbols: vscode.DocumentSymbol[] = []
     const lines = document.getText().split("\n")

client/src/common/server.ts

@@ -2,7 +2,7 @@
 // Licensed under the MIT License.
 
 import * as fsapi from "fs-extra"
-import { Disposable, env, LogOutputChannel } from "vscode"
+import { Disposable, env, LogOutputChannel, workspace } from "vscode"
 import { State } from "vscode-languageclient"
 import {
     LanguageClient,
@@ -24,6 +24,13 @@ import { isVirtualWorkspace } from "./vscodeapi"
 
 export type IInitOptions = { settings: ISettings[]; globalSettings: ISettings }
 
+let _disposables: Disposable[] = []
+
+export function disposeServerResources(): void {
+    _disposables.forEach((disposable) => disposable.dispose())
+    _disposables = []
+}
+
 async function createServer(
     settings: ISettings,
     serverId: string,
@@ -63,6 +70,7 @@ async function createServer(
     }
 
     // Options to control the language client
+    const tclFileWatcher = workspace.createFileSystemWatcher("**/*.tcl")
     const clientOptions: LanguageClientOptions = {
         // Register the server for python documents
         documentSelector: isVirtualWorkspace()
@@ -76,13 +84,16 @@ async function createServer(
         outputChannel: outputChannel,
         traceOutputChannel: outputChannel,
         revealOutputChannelOn: RevealOutputChannelOn.Never,
+        synchronize: {
+            fileEvents: tclFileWatcher
+        },
         initializationOptions
     }
 
+    _disposables.push(tclFileWatcher)
     return new LanguageClient(serverId, serverName, serverOptions, clientOptions)
 }
 
-let _disposables: Disposable[] = []
 export async function restartServer(
     serverId: string,
     serverName: string,
@@ -92,8 +103,7 @@ export async function restartServer(
     if (lsClient) {
         traceInfo(`Server: Stop requested`)
         await lsClient.stop()
-        _disposables.forEach((d) => d.dispose())
-        _disposables = []
+        disposeServerResources()
     }
     const projectRoot = await getProjectRoot()
     const workspaceSetting = await getWorkspaceSettings(serverId, projectRoot, true)
@@ -122,6 +132,7 @@ export async function restartServer(
         await newLSClient.start()
     } catch (ex) {
         traceError(`Server: Start failed: ${ex}`)
+        disposeServerResources()
         return undefined
     }