Add VS Code extension and discovery tools

Introduce a VS Code extension (extensions/vscode/) that automatically
installs, configures, and manages the MCP server. It bridges with
vscode-codeql to watch databases and query run results, resolves the
CodeQL CLI, and provides an MCP server definition provider.

Add two new MCP server tools:
- list_codeql_databases: discovers databases in configured base dirs
- list_query_run_results: discovers per-run result directories

Supporting changes:
- Add discovery-config module for env-var-based directory parsing
- Set timeout: 0 for fresh-process CodeQL commands in cli-executor
- Add .vscode workspace configuration (launch, tasks, mcp)
- Add root tsconfig project reference for the extension
- Add integration test fixtures for the new tools

Author: data-douser

.vscode/launch.json

@@ -0,0 +1,34 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Run Extension",
+      "type": "extensionHost",
+      "request": "launch",
+      "args": [
+        "--extensionDevelopmentPath=${workspaceFolder}/extensions/vscode"
+      ],
+      "outFiles": [
+        "${workspaceFolder}/extensions/vscode/dist/**/*.js",
+        "${workspaceFolder}/extensions/vscode/dist/**/*.cjs"
+      ],
+      "preLaunchTask": "npm: bundle - extensions/vscode",
+      "sourceMaps": true
+    },
+    {
+      "name": "Extension Tests",
+      "type": "extensionHost",
+      "request": "launch",
+      "args": [
+        "--extensionDevelopmentPath=${workspaceFolder}/extensions/vscode",
+        "--extensionTestsPath=${workspaceFolder}/extensions/vscode/dist/test/suite/index.cjs"
+      ],
+      "outFiles": [
+        "${workspaceFolder}/extensions/vscode/dist/**/*.js",
+        "${workspaceFolder}/extensions/vscode/dist/**/*.cjs"
+      ],
+      "preLaunchTask": "npm: bundle - extensions/vscode",
+      "sourceMaps": true
+    }
+  ]
+}

.vscode/mcp.json

@@ -0,0 +1,12 @@
+{
+	"servers": {
+		"ql-mcp": {
+			"type": "stdio",
+			"command": "node",
+			"args": [
+				"/Users/data-douser/Git/advanced-security/codeql-development-mcp-server/server/dist/codeql-development-mcp-server.js"
+			]
+		}
+	},
+	"inputs": []
+}

.vscode/tasks.json

@@ -0,0 +1,51 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "build",
+      "path": "extensions/vscode",
+      "label": "npm: build - extensions/vscode",
+      "group": "build",
+      "problemMatcher": [],
+      "detail": "Clean, lint, and bundle the VS Code extension"
+    },
+    {
+      "type": "npm",
+      "script": "bundle",
+      "path": "extensions/vscode",
+      "label": "npm: bundle - extensions/vscode",
+      "group": "build",
+      "problemMatcher": [],
+      "detail": "Bundle the VS Code extension (no lint)"
+    },
+    {
+      "type": "npm",
+      "script": "watch",
+      "path": "extensions/vscode",
+      "label": "npm: watch - extensions/vscode",
+      "group": "build",
+      "isBackground": true,
+      "problemMatcher": [],
+      "detail": "Watch and rebuild the VS Code extension on changes"
+    },
+    {
+      "type": "npm",
+      "script": "test",
+      "path": "extensions/vscode",
+      "label": "npm: test - extensions/vscode",
+      "group": "test",
+      "problemMatcher": [],
+      "detail": "Run unit tests for the VS Code extension"
+    },
+    {
+      "type": "npm",
+      "script": "build",
+      "path": "server",
+      "label": "npm: build - server",
+      "group": "build",
+      "problemMatcher": [],
+      "detail": "Build the MCP server"
+    }
+  ]
+}

client/integration-tests/primitives/tools/list_codeql_databases/no_dirs_configured/README.md

@@ -0,0 +1,6 @@
+# `list_codeql_databases` - no_dirs_configured
+
+## Purpose
+
+Tests the `list_codeql_databases` tool when `CODEQL_DATABASES_BASE_DIRS` is not set.
+The tool should return a helpful message explaining how to configure it.

client/integration-tests/primitives/tools/list_codeql_databases/no_dirs_configured/after/monitoring-state.json

@@ -0,0 +1,14 @@
+{
+  "sessions": [
+    {
+      "id": "integration_test_session",
+      "calls": [
+        {
+          "tool": "list_codeql_databases",
+          "timestamp": "2025-09-25T16:06:00.000Z",
+          "status": "success"
+        }
+      ]
+    }
+  ]
+}

client/integration-tests/primitives/tools/list_codeql_databases/no_dirs_configured/before/monitoring-state.json

@@ -0,0 +1,4 @@
+{
+  "sessions": [],
+  "parameters": {}
+}

client/integration-tests/primitives/tools/list_codeql_databases/no_dirs_configured/test-config.json

@@ -0,0 +1,4 @@
+{
+  "toolName": "list_codeql_databases",
+  "arguments": {}
+}

client/integration-tests/primitives/tools/list_query_run_results/no_dirs_configured/README.md

@@ -0,0 +1,6 @@
+# `list_query_run_results` - no_dirs_configured
+
+## Purpose
+
+Tests the `list_query_run_results` tool when `CODEQL_QUERY_RUN_RESULTS_DIRS` is not set.
+The tool should return a helpful message explaining how to configure it.

client/integration-tests/primitives/tools/list_query_run_results/no_dirs_configured/after/monitoring-state.json

@@ -0,0 +1,14 @@
+{
+  "sessions": [
+    {
+      "id": "integration_test_session",
+      "calls": [
+        {
+          "tool": "list_query_run_results",
+          "timestamp": "2025-09-25T16:06:00.000Z",
+          "status": "success"
+        }
+      ]
+    }
+  ]
+}

client/integration-tests/primitives/tools/list_query_run_results/no_dirs_configured/before/monitoring-state.json

@@ -0,0 +1,4 @@
+{
+  "sessions": [],
+  "parameters": {}
+}