feat(turd): show what each choice changes + recipe-comparison diffs (#70)

* fix(db): build test databases from migrations, not schema push

makeTestDb generated DDL straight from schema.ts, so a test db never
recorded the drizzle migration journal. The first incremental ALTER
migration then re-added a column the push had already created. Provision
test dbs the way production does — apply the bundled migrations — so tests
exercise the real path and incremental migrations don't collide.

* feat(turd): surface what each choice changes + recipe-comparison diffs

The assistant and the TURD page only knew about branches that *replace* a
recipe (the turd_replacements table), so branches that unlock a brand-new
recipe were invisible — the agent reported moondrop-upgrade as a single
choice when it actually has three.

- turdChoices tool + recipeInfo enrichment walk the tech-prerequisite graph,
  so the agent sees every branch: its description, the recipes it swaps
  (old->new) or newly unlocks, and its modules.
- Import tech descriptions (new technologies.description column).
- /turd page: each choice lists its concrete recipe changes with icons and
  descriptions instead of a bare 'N recipes' count; effect pills color-coded.
- Recipe-comparison hover (reusable for Py recipe tiers): in/out diff, colored
  time, base per-second throughput with % change. A choice's module is applied
  to a swapped recipe's rate only when it runs in the affected building (skipped
  for building-construction recipes); productivity skips ignored-by-productivity
  outputs like barrels.

* fix(assistant): warn when no OpenRouter key is set

Sending a message with no key configured returned a 500 the UI never
surfaced, so the conversation just died silently. Show an up-front banner
(linking to Settings) when no key is stored or in the env, and render the
request error if a send fails anyway.

Author: ApocDev

README.md

@@ -39,7 +39,10 @@ source](#setup) to hack on it.
 - **Browse the data.** A searchable catalogue of every item, fluid, and recipe in
   your exact mod set — used-in / produced-by, ingredients, products, machines.
 - **Track TURD choices.** Py's "There's Usually a Recipe Difference" tech upgrades
-  are first-class: pick a path and every block re-solves against it.
+  are first-class: each master shows every branch — its description, the recipes it
+  swaps or newly unlocks, and a hover diff of what actually changes (inputs,
+  outputs, and base throughput per second). Pick a path and every block re-solves
+  against it.
 - **Plan with AI.** An assistant (via OpenRouter) drafts whole production chains
   and multi-block plans using tools over the recipe data, honouring what you can
   build _now_ vs. _after research_.

app/drizzle/0001_add_tech_description.sql

@@ -0,0 +1 @@
+ALTER TABLE `technologies` ADD `description` text;