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]>

test/helpers.js

@@ -27,6 +27,7 @@ export async function setup(env = {}, appOptions = {}) {
 		 CREATE TABLE roast_plans(id uuid PRIMARY KEY DEFAULT gen_random_uuid(),user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,plan jsonb NOT NULL,created_at timestamptz DEFAULT now(),updated_at timestamptz DEFAULT now());
 		 CREATE TABLE app_settings(key text PRIMARY KEY,value text NOT NULL);
 		 INSERT INTO app_settings VALUES('signup_enabled','true');
+		 INSERT INTO app_settings VALUES('llm_model','');
 		 CREATE TABLE password_reset_tokens(token_hash text PRIMARY KEY,user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,expires_at timestamptz NOT NULL,created_at timestamptz DEFAULT now());
 		 CREATE TABLE audit_events(id uuid PRIMARY KEY DEFAULT gen_random_uuid(),actor_user_id uuid REFERENCES users(id) ON DELETE SET NULL,action text NOT NULL,target text,created_at timestamptz DEFAULT now());
 		 CREATE TABLE green_bean_lots(id uuid PRIMARY KEY DEFAULT gen_random_uuid(),user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,origin text NOT NULL,variety text NOT NULL DEFAULT '',process text NOT NULL DEFAULT '',producer text NOT NULL DEFAULT '',purchase_date date,initial_weight_g numeric NOT NULL,remaining_weight_g numeric NOT NULL,cost_total numeric,moisture_pct numeric,density_g_l numeric,notes text NOT NULL DEFAULT '',archived boolean NOT NULL DEFAULT false,created_at timestamptz DEFAULT now(),updated_at timestamptz DEFAULT now());