chore: improve DevContainer and VS Code dev experience

- Fix DevContainer image versions to match project requirements
- Add VS Code tasks.json for one-click build/run/watch
- Ensure postCreateCommand installs all dev dependencies

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SamMorrowDrums

.vscode/tasks.json

@@ -0,0 +1,32 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "Run (stdio)",
+      "type": "shell",
+      "command": "uv run mcp-python-starter --stdio",
+      "group": "test"
+    },
+    {
+      "label": "Run (HTTP)",
+      "type": "shell",
+      "command": "uv run mcp-python-starter --http",
+      "group": "test"
+    },
+    {
+      "label": "Lint",
+      "type": "shell",
+      "command": "uv run ruff check mcp_starter/",
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      }
+    },
+    {
+      "label": "Test",
+      "type": "shell",
+      "command": "uv run pytest",
+      "group": "test"
+    }
+  ]
+}