feat: custom recipe cover color/icon + mute auto placeholder palette (v0.51.0)

Two changes to the no-photo cover placeholder shipped last version:

1. Muted the gradient palette (100/40-opacity tints instead of solid -200/
   -950 stops) — the original was too saturated next to real cover photos
   in the same grid, per feedback.
2. New coverIcon/coverColor columns on recipes (nullable text, migration
   0048, additive-only) let the author pin a specific color+icon from the
   recipe editor instead of the automatic per-id pick. getRecipePlaceholder
   now checks these first, falling back to the deterministic hash pick when
   unset — existing recipes are unaffected until edited.

Wired coverIcon/coverColor through every explicit-column recipe select
that feeds a grid card (explore trending/recent, search, feed, for-you) —
the relational-query call sites (recipes page, collections, profile pages)
already return all columns and needed no changes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

packages/db/src/migrations/0048_normal_shiver_man.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "recipes" ADD COLUMN "cover_icon" text;--> statement-breakpoint
+ALTER TABLE "recipes" ADD COLUMN "cover_color" text;

packages/db/src/migrations/meta/_journal.json

@@ -337,6 +337,13 @@
       "when": 1784394631882,
       "tag": "0047_acoustic_goblin_queen",
       "breakpoints": true
+    },
+    {
+      "idx": 48,
+      "version": "7",
+      "when": 1784449674049,
+      "tag": "0048_normal_shiver_man",
+      "breakpoints": true
     }
   ]
 }

packages/db/src/schema/recipes.ts

@@ -49,6 +49,10 @@ export const recipes = pgTable("recipes", {
   cookMins: integer("cook_mins"),
   tags: text("tags").array().notNull().default([]),
   isBatchCook: boolean("is_batch_cook").notNull().default(false),
+  // User-chosen cover for when there's no photo — null falls back to the
+  // deterministic hash-based placeholder (see lib/recipe-placeholder.ts).
+  coverIcon: text("cover_icon"),
+  coverColor: text("cover_color"),
   createdAt: timestamp("created_at").notNull().defaultNow(),
   updatedAt: timestamp("updated_at").notNull().defaultNow(),
 }, (t) => [