feat(db): add migrations for user reputation and channel culture tables

Adds new database schema migrations to support the implementation of
user reputation tracking and channel-specific culture context.

- Creates migration `0005_large_squadron_sinister.sql` containing
  `user_reputations` and `channel_cultures` tables.
- Updates Drizzle migration journal to include the new migration step.
- Adds `fix_prompt.py` utility for managing prompt adjustments.

services/discord-gateway/drizzle/migrations/0005_large_squadron_sinister.sql

@@ -0,0 +1,21 @@
+CREATE TABLE "channel_cultures" (
+	"channel_id" text PRIMARY KEY NOT NULL,
+	"guild_id" text NOT NULL,
+	"culture_summary" text NOT NULL,
+	"last_analyzed_at" bigint NOT NULL
+);
+--> statement-breakpoint
+CREATE TABLE "user_reputations" (
+	"user_id" text PRIMARY KEY NOT NULL,
+	"guild_id" text NOT NULL,
+	"trust_score" integer DEFAULT 50 NOT NULL,
+	"clean_message_streak" integer DEFAULT 0 NOT NULL,
+	"total_infractions" integer DEFAULT 0 NOT NULL,
+	"last_infraction_at" bigint,
+	"created_at" bigint NOT NULL,
+	"updated_at" bigint NOT NULL
+);
+--> statement-breakpoint
+CREATE INDEX "idx_channel_cultures_guild_id" ON "channel_cultures" USING btree ("guild_id");--> statement-breakpoint
+CREATE INDEX "idx_user_reputations_guild_id" ON "user_reputations" USING btree ("guild_id");--> statement-breakpoint
+CREATE INDEX "idx_user_reputations_trust_score" ON "user_reputations" USING btree ("trust_score");

services/discord-gateway/drizzle/migrations/meta/_journal.json

@@ -36,6 +36,13 @@
       "when": 1780418800000,
       "tag": "0004_drop_unused_ai_columns",
       "breakpoints": true
+    },
+    {
+      "idx": 5,
+      "version": "7",
+      "when": 1780657801437,
+      "tag": "0005_large_squadron_sinister",
+      "breakpoints": true
     }
   ]
 }