feat: port alt-text and query commands from Cordelia

Adds owner-only /alt-text and /query slash commands, migrating
Cordelia's AI functionality into Amari with updated style and auth.

src/commands/altText.ts

@@ -0,0 +1,153 @@
+/**
+ * @copyright NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
+import { ids } from "../config/ids.js";
+import { anthropic } from "../utils/anthropic.js";
+import { logger } from "../utils/logger.js";
+import { amariPersonality } from "../utils/makeAiRequest.js";
+import type { Amari } from "../interfaces/amari.js";
+
+type ValidImageMediaType =
+  | "image/gif"
+  | "image/jpeg"
+  | "image/png"
+  | "image/webp";
+
+const validImageTypes = new Set<string>([
+  "image/gif",
+  "image/jpeg",
+  "image/png",
+  "image/webp",
+]);
+
+const isValidContentType = (type: string): type is ValidImageMediaType => {
+  return validImageTypes.has(type);
+};
+
+const altTextSystemPrompt = `${amariPersonality}\n\nYour role in this`
+  + " conversation is to generate descriptive and accessible alt-text for the"
+  + " user's image. Be as descriptive as possible. Do not include ANYTHING in"
+  + " your response EXCEPT the actual alt-text. Wrap the text in a multi-line"
+  + " code block for easy copying.";
+
+/**
+ * Downloads an image and asks Claude to generate alt-text for it.
+ * @param imageUrl - The URL of the image to process.
+ * @param contentType - The validated MIME type of the image.
+ * @returns The generated alt-text, or null if the request fails.
+ */
+const generateAltText = async(
+  imageUrl: string,
+  contentType: ValidImageMediaType,
+): Promise<string | null> => {
+  const downloadRequest = await fetch(imageUrl);
+  const blob = await downloadRequest.arrayBuffer();
+  const base64 = Buffer.from(blob).toString("base64");
+
+  const response = await anthropic.messages.create({
+    // eslint-disable-next-line @typescript-eslint/naming-convention -- Anthropic API field.
+    max_tokens: 2000,
+    messages:   [
+      {
+        content: [
+          {
+            source: {
+              data:       base64,
+              // eslint-disable-next-line @typescript-eslint/naming-convention -- Anthropic API field.
+              media_type: contentType,
+              type:       "base64",
+            },
+            type: "image",
+          },
+        ],
+        role: "user",
+      },
+    ],
+    model:  "claude-sonnet-4-6",
+    system: altTextSystemPrompt,
+  });
+
+  const textContent = response.content.find((block) => {
+    return block.type === "text";
+  });
+
+  return textContent?.type === "text"
+    ? textContent.text
+    : null;
+};
+
+/**
+ * Validates the attachment is a supported image, downloads it, and sends it
+ * to Claude to generate descriptive alt-text.
+ * @param _amari - The Amari instance (unused but kept for handler consistency).
+ * @param interaction - The Discord slash command interaction.
+ */
+// eslint-disable-next-line max-lines-per-function, complexity -- Image validation requires multiple checks.
+export const altText = async(
+  _amari: Amari,
+  interaction: ChatInputCommandInteraction,
+): Promise<void> => {
+  if (interaction.user.id !== ids.users.naomi) {
+    await interaction.reply({
+      content: "This command is restricted to Naomi.",
+      flags:   [ MessageFlags.Ephemeral ],
+    });
+    return;
+  }
+
+  const image = interaction.options.getAttachment("image", true);
+  const { contentType, height, width, size, url } = image;
+
+  if (
+    contentType === null
+    || !isValidContentType(contentType)
+    || height === null
+    || width === null
+  ) {
+    await interaction.reply({
+      content: "That does not appear to be a valid image.",
+      flags:   [ MessageFlags.Ephemeral ],
+    });
+    return;
+  }
+
+  if (size > 5 * 1024 * 1024) {
+    await interaction.reply({
+      // eslint-disable-next-line stylistic/max-len -- Long user-facing string.
+      content: "That image is too large. Please provide an image that is less than 5MB.",
+      flags:   [ MessageFlags.Ephemeral ],
+    });
+    return;
+  }
+
+  if (height > 8000 || width > 8000) {
+    await interaction.reply({
+      // eslint-disable-next-line stylistic/max-len -- Long user-facing string.
+      content: "That image is too large. Please provide an image less than 8000 pixels in either dimension.",
+      flags:   [ MessageFlags.Ephemeral ],
+    });
+    return;
+  }
+
+  await interaction.deferReply({ flags: [ MessageFlags.Ephemeral ] });
+
+  try {
+    const result = await generateAltText(url, contentType);
+
+    await interaction.editReply({
+      content: result
+        ?? "I'm sorry, I wasn't able to generate alt-text for that image.",
+    });
+  } catch (error) {
+    await logger.error("alt-text command", error instanceof Error
+      ? error
+      : new Error(String(error)));
+    await interaction.editReply({
+      content: "Something went wrong whilst generating the alt-text.",
+    });
+  }
+};