feat: rewrite as moderation bot (Keiko)

Replaces the old AI companion bot with a full Discord moderation system.

Commands: warn, mute, unmute, kick, softban, ban, unban, prune
Logging: member join/leave, activity (messages/threads/voice), mod actions
Audit log: captures manual bans, kicks, timeouts, and unbans
Sanctions: posts to Hikari sanction API for all applicable actions

All commands are ephemeral and use Components v2. Permission and role
hierarchy checks are enforced on every applicable command.

src/commands/ban.ts

@@ -0,0 +1,157 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+/* eslint-disable max-lines-per-function -- Command handlers have many validation and action steps */
+/* eslint-disable max-statements -- Command handlers have many validation and action steps */
+/* eslint-disable complexity -- Command handlers have multiple validation branches */
+
+import {
+  InteractionContextType,
+  PermissionFlagsBits,
+  SlashCommandBuilder,
+} from "discord.js";
+import { logModerationAction } from "../modules/logModAction.js";
+import { sendSanction } from "../modules/sendSanction.js";
+import { errorReply, successReply } from "../utils/components.js";
+import { logger } from "../utils/logger.js";
+import type { Command } from "../interfaces/command.js";
+
+const banCommand: Command = {
+  data: new SlashCommandBuilder().
+    setName("ban").
+    setDescription("Ban a member from the server.").
+    setDefaultMemberPermissions(PermissionFlagsBits.BanMembers).
+    setContexts([ InteractionContextType.Guild ]).
+    addUserOption((option) => {
+      return option.
+        setName("user").
+        setDescription("The member to ban.").
+        setRequired(true);
+    }).
+    addStringOption((option) => {
+      return option.
+        setName("reason").
+        setDescription("The reason for the ban.").
+        setRequired(true).
+        setMaxLength(512);
+    }).
+    addIntegerOption((option) => {
+      return option.
+        setName("days").
+        setDescription(
+          "Days of message history to delete (0–7). Defaults to 0.",
+        ).
+        setRequired(false).
+        setMinValue(0).
+        setMaxValue(7);
+    }),
+
+  execute: async(interaction) => {
+    await interaction.deferReply({ ephemeral: true });
+
+    const hasPermission = interaction.memberPermissions?.has(
+      PermissionFlagsBits.BanMembers,
+    );
+    if (hasPermission !== true) {
+      await interaction.editReply(
+        errorReply(
+          "Insufficient Permissions",
+          "You do not have permission to use this command.",
+        ),
+      );
+      return;
+    }
+
+    const target = interaction.options.getUser("user", true);
+    const reason = interaction.options.getString("reason", true);
+    const days = interaction.options.getInteger("days") ?? 0;
+
+    if (target.bot) {
+      await interaction.editReply(
+        errorReply("Invalid Target", "You cannot ban a bot."),
+      );
+      return;
+    }
+
+    if (target.id === interaction.user.id) {
+      await interaction.editReply(
+        errorReply("Invalid Target", "You cannot ban yourself."),
+      );
+      return;
+    }
+
+    const member = interaction.guild?.members.cache.get(target.id);
+
+    if (member) {
+      const selfMember = interaction.guild?.members.cache.get(
+        interaction.user.id,
+      );
+      if (
+        selfMember
+        && member.roles.highest.position >= selfMember.roles.highest.position
+      ) {
+        await interaction.editReply(
+          errorReply(
+            "Insufficient Permissions",
+            "You cannot ban someone with an equal or higher role.",
+          ),
+        );
+        return;
+      }
+
+      try {
+        await target.send(
+          `You have been banned from **${interaction.guild?.name ?? "the server"}**.\n**Reason:** ${reason}`,
+        );
+      } catch {
+        // DMs may be closed; continue without failing the command.
+      }
+    }
+
+    try {
+      await interaction.guild?.bans.create(target.id, {
+        deleteMessageSeconds: days * 86_400,
+        reason:               reason,
+      });
+    } catch {
+      await interaction.editReply(
+        errorReply(
+          "Action Failed",
+          "Failed to ban the member. Check my permissions and role hierarchy.",
+        ),
+      );
+      return;
+    }
+
+    const sanctionNumber = await sendSanction({
+      reason:   reason,
+      type:     "ban",
+      username: target.username,
+      uuid:     target.id,
+    });
+
+    await logModerationAction(interaction.client, {
+      action:         "Member Banned",
+      emoji:          "🔨",
+      moderatorTag:   interaction.user.username,
+      reason:         reason,
+      sanctionNumber: sanctionNumber,
+      source:         "Command",
+      targetId:       target.id,
+      targetTag:      target.username,
+    });
+
+    await interaction.editReply(
+      successReply(
+        "Member Banned",
+        `**User**: ${target.username} (\`${target.id}\`)\n**Days Deleted**: ${days.toString()}\n**Reason**: ${reason}`,
+      ),
+    );
+  },
+};
+
+void logger.log("debug", "Ban command loaded.");
+
+export { banCommand };