refactor: consolidate config types and remove file-based config

Tickets: #2, #3

- Remove duplicate type definitions from shared/lib/config.ts
- Import types from schema files (game-settings.ts, guild-settings.ts)
- Add GuildConfig interface to guild-settings.ts schema
- Rename ModerationConfig to ModerationCaseConfig in moderation.service.ts
- Delete shared/config/config.json and shared/scripts/migrate-config-to-db.ts
- Update settings API to use gameSettingsService exclusively
- Return DB format (strings) from API instead of runtime BigInts
- Fix moderation service tests to pass config as parameter

Breaking Changes:
- Removes legacy file-based configuration system
- API now returns database format with string values for BigInt fields

shared/scripts/migrate-config-to-db.ts

@@ -1,51 +0,0 @@
-import { guildSettingsService } from "@shared/modules/guild-settings/guild-settings.service";
-import { config } from "@shared/lib/config";
-import { env } from "@shared/lib/env";
-
-async function migrateConfigToDatabase() {
-    const guildId = env.DISCORD_GUILD_ID;
-
-    if (!guildId) {
-        console.error("DISCORD_GUILD_ID not set. Cannot migrate config.");
-        console.log("Set DISCORD_GUILD_ID in your environment to migrate config.");
-        process.exit(1);
-    }
-
-    console.log(`Migrating config for guild ${guildId}...`);
-
-    const existing = await guildSettingsService.getSettings(guildId);
-    if (existing) {
-        console.log("Guild settings already exist in database:");
-        console.log(JSON.stringify(existing, null, 2));
-        console.log("\nSkipping migration. Delete existing settings first if you want to re-migrate.");
-        return;
-    }
-
-    await guildSettingsService.upsertSettings({
-        guildId,
-        studentRoleId: config.studentRole ?? undefined,
-        visitorRoleId: config.visitorRole ?? undefined,
-        colorRoleIds: config.colorRoles ?? [],
-        welcomeChannelId: config.welcomeChannelId ?? undefined,
-        welcomeMessage: config.welcomeMessage ?? undefined,
-        feedbackChannelId: config.feedbackChannelId ?? undefined,
-        terminalChannelId: config.terminal?.channelId ?? undefined,
-        terminalMessageId: config.terminal?.messageId ?? undefined,
-        moderationLogChannelId: config.moderation?.cases?.logChannelId ?? undefined,
-        moderationDmOnWarn: config.moderation?.cases?.dmOnWarn ?? true,
-        moderationAutoTimeoutThreshold: config.moderation?.cases?.autoTimeoutThreshold ?? undefined,
-    });
-
-    console.log("✅ Migration complete!");
-    console.log("\nGuild settings are now stored in the database.");
-    console.log("You can manage them via:");
-    console.log("  - /settings command in Discord");
-    console.log("  - API endpoints at /api/guilds/:guildId/settings");
-}
-
-migrateConfigToDatabase()
-    .then(() => process.exit(0))
-    .catch((error) => {
-        console.error("Migration failed:", error);
-        process.exit(1);
-    });