Add admin LLM model setting; rename Pi to LLM in the UI; drop table Review column

- New server/llm.js consolidates ModelRuntime + model selection: admin
  setting (app_settings.llm_model) > LLM_MODEL/PREFILL_MODEL env > first
  available; used by both prefill and roast evaluation
- GET/PUT /api/admin/llm lists configured models and stores the choice
  (validated against the list; empty = auto; audited); admin page gains
  an LLM section with a model picker
- All user-facing 'Pi agent' wording is now 'LLM'; no_model error message
  no longer references the pi CLI
- /roasts table: Review column removed (review lives in the detail view)

Co-Authored-By: Claude Fable 5 <[email protected]>

public/js/admin.js

@@ -93,6 +93,64 @@ function wireSignupToggle() {
 	});
 }
 
+async function loadLlm() {
+	const select = document.getElementById("llm-model-select");
+	const note = document.getElementById("llm-model-note");
+	try {
+		const { current, models, modelsError } = await api("/api/admin/llm");
+		const auto = document.createElement("option");
+		auto.value = "";
+		auto.textContent = "Auto (first available model)";
+		select.replaceChildren(
+			auto,
+			...models.map((model) => {
+				const option = document.createElement("option");
+				option.value = model.key;
+				option.textContent = `${model.name} (${model.provider})`;
+				return option;
+			}),
+		);
+		// A previously-saved model that is no longer configured must still show as selected
+		// rather than silently displaying Auto while the server keeps trying the saved one.
+		if (current && !models.some((model) => model.key === current)) {
+			const missing = document.createElement("option");
+			missing.value = current;
+			missing.textContent = `${current} (no longer configured)`;
+			select.append(missing);
+		}
+		select.value = current;
+		note.textContent = modelsError
+			? "No models are configured on the server — reviews and prefill will fail until one is set up."
+			: current
+				? ""
+				: models.length
+					? `Auto currently resolves to ${models[0].name} (${models[0].provider}).`
+					: "";
+	} catch {
+		note.textContent = "Could not load LLM settings.";
+	}
+}
+
+function wireLlmSave() {
+	const button = document.getElementById("llm-model-save");
+	button.addEventListener("click", async () => {
+		button.disabled = true;
+		try {
+			const model = document.getElementById("llm-model-select").value;
+			await api("/api/admin/llm", {
+				method: "PUT",
+				body: JSON.stringify({ model }),
+			});
+			showToast(model ? "LLM model saved." : "LLM model set to auto.");
+			await loadLlm();
+		} catch (error) {
+			showToast(error.message, "fail");
+		} finally {
+			button.disabled = false;
+		}
+	});
+}
+
 function roleBadge(user) {
 	return user.role === "admin"
 		? `<span class="badge badge-admin">Admin</span>`
@@ -317,12 +375,14 @@ async function init() {
 	if (!user) return;
 	currentUserId = user.id;
 	wireSignupToggle();
+	wireLlmSave();
 	await Promise.all([
 		loadMetrics(),
 		loadResetLinks(),
 		loadUsers(),
 		loadPlans(),
 		loadAudit(),
+		loadLlm(),
 	]);
 }