docs: add infrastructure task tracking and Robot Framework deps

- Rename Docs/Tasks.md → Docs/tasks.md (case fix)
- Add comprehensive task docs for INFRA-1 (server startup) and INFRA-2 (teardown)
- Add test-robot make target
- Add robotframework, browser, requests, jsonlibrary to requirements.txt

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

Docs/runner.csx

@@ -24,7 +24,7 @@ Console.CancelKeyPress += (_, e) =>
 
 // ── Paths ─────────────────────────────────────────────────────────────────────
 var repoRoot = Directory.GetCurrentDirectory();
-var tasksFile = Path.Combine(repoRoot, "Docs", "Tasks.md");
+var tasksFile = Path.Combine(repoRoot, "Docs", "tasks.md");
 
 if (!File.Exists(tasksFile))
 {
@@ -102,7 +102,7 @@ for (int i = 0; i < items.Count; i++)
 
     // Step 1 — run the task prompt
     await RunCopilot(Enumerable.Empty<string>(), $"/caveman full");
-    await RunCopilot(new[] { "--continue" }, $"read ./Docs/instructions.md. {item}");
+    await RunCopilot(new[] { "--continue" }, $"{item}");
     if (cts.IsCancellationRequested) break;
 
     // Step 2 — confirm completion in the same chat session