fix: resolve 500 errors from model returning trivial status objects (root cause + v0.2 prompt fix)

Two bugs were causing the model to return {"status":"ok"} / {"status":"ready"}
instead of structured reconstruction data, resulting in POST /api/analyse 500:

1. DOUBLE-WRAPPING BUG (lib/llm/provider.js):
   generateReconstruction() called buildPrompt(scenario) on input that was
   already a fully-built prompt string from analyseScenario(). This wrapped the
   v0.1 prompt (~5000+ chars) in another template layer, producing incomprehensible
   output that the model could not parse as structured JSON.
   Fix: Pass scenario through directly (it is ALREADY a built prompt).

2. MISSING JSON SPEC (prompts/reconstruct-v0.2.md):
   The v0.2 prompt template said 'matching the structure exactly' but never
   defined what that structure was. The model invented its own field names
   (input_classification, reasoning_mode, anchors) with snake_case instead of
   camelCase, which failed Zod validation -> 500 errors.
   Fix: Added explicit JSON schema section with exact key names, enum values,
   and nested structure matching the Zod validation layer.

Additionally:
- Refactored route to use analyseScenario from lib/analysis (centralized)
- Added lib/analysis.js with shared analysis logic
- Updated components to display promptVersion and validation errors
- Added lib/reconstruction/prompt.js v0.1/v0.2 versioning
- Added lib/reconstruction/schema.js v0.2 Zod schemas
- Added debug tool scripts, evaluation results, and comparison findings

lib/llm/provider.js

@@ -93,11 +93,9 @@ async function detectChatSupport(baseUrl) {
 
 class OllamaLlmProvider {
   async generateReconstruction(scenario, modelName) {
-    const { buildPrompt } = await import("@/lib/reconstruction/prompt");
-    
-    let rawPrompt = buildPrompt(scenario);
-    // Stronger JSON hint since we can't use format:json on older Ollama
-    const prompt = rawPrompt + `\n\nReturn ONLY a valid JSON object starting with { and ending with }. Do NOT include any text before the opening brace or after the closing brace. Do NOT wrap in markdown backticks.`;
+    // scenario is ALREADY a fully-built prompt text (built by analyseScenario).
+    // Do NOT call buildPrompt() again — that would double-wrap the prompt.
+    const prompt = scenario;
 
     const baseUrl = process.env.OLLAMA_BASE_URL;
     if (!baseUrl) throw new Error("OLLAMA_BASE_URL is not set");