feat: add slash commands and context menu command (#16)

## Summary

This PR adds a suite of slash commands and a context menu command to Amari, along with shared utilities and quality improvements across the board.

### New Commands
- **`/create-issue`** — generates a GitHub issue on a specified repo using AI-drafted content (title, description, acceptance criteria)
- **`/create-task`** — creates a task in Naomi's Leantime instance with an AI-drafted description and configurable priority
- **`/onboard-mentee`** — automates the mentorship onboarding flow (GitHub invite, forum thread, role assignment)
- **Forward to Owner** (context menu, message command) — forwards any message to Naomi with action buttons (contributed by @teklu)

### Shared Utilities
- **`src/utils/makeAiRequest.ts`** — a single wrapper around the Anthropic SDK for all AI calls, with Amari's personality prompt baked in and full error handling
- **`src/events/handleInteractionCreate.ts`** — extracted interaction handler (was inline in `index.ts`) to keep complexity under control

### Quality Improvements
- `ephemeral: true` → `flags: [ MessageFlags.Ephemeral ]` (deprecated API removed)
- Full `try/catch` + `logger.error` audit across all modules (`logMenteeJoin`, `checkAchievements`, `processMentorshipRole`, `processGitHubEvent`)
- `deployGlobal.ts` replaced with a static `commands.json` payload for manual registration
- Amari's personality prompt updated to reflect her actual character — warm, observant, and relentlessly caring

### Notes
- `CLIENT_ID` is needed in 1Password at `op://Environment Variables - Naomi/Amari/client id` for the `commands.json` registration call
- The forward-to-owner command (PR #13, contributed by @teklu) is fully preserved with original commit authorship

✨ This PR was created with help from Hikari~ 🌸

Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-authored-by: Teklu <tekluabayneh@gmail.com>
Reviewed-on: #16
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/modules/checkAchievements.ts

@@ -23,6 +23,7 @@ import {
   type MessageActionRowComponentBuilder,
 } from "discord.js";
 import { ids } from "../config/ids.js";
+import { logger } from "../utils/logger.js";
 import type { Amari } from "../interfaces/amari.js";
 
 const username = "naomilgbt";
@@ -91,28 +92,34 @@ export const checkRetroAchievements = async(
     return;
   }
 
-  const auth = buildAuthorization({ username, webApiKey });
+  try {
+    const auth = buildAuthorization({ username, webApiKey });
 
-  const recentAchievements = await getUserRecentAchievements(auth, {
-    recentMinutes: 10,
-    username:      username,
-  });
-
-  if (recentAchievements.length <= 0) {
-    return;
-  }
-
-  const channel = amari.discord.channels.cache.get(ids.channels.gaming)
-    ?? await amari.discord.channels.fetch(ids.channels.gaming);
-
-  if (channel?.isSendable() !== true) {
-    return;
-  }
-
-  await Promise.all(recentAchievements.map(async(achievement) => {
-    await channel.send({
-      components: constructComponents(achievement),
-      flags:      [ MessageFlags.IsComponentsV2 ],
+    const recentAchievements = await getUserRecentAchievements(auth, {
+      recentMinutes: 10,
+      username:      username,
     });
-  }));
+
+    if (recentAchievements.length <= 0) {
+      return;
+    }
+
+    const channel = amari.discord.channels.cache.get(ids.channels.gaming)
+      ?? await amari.discord.channels.fetch(ids.channels.gaming);
+
+    if (channel?.isSendable() !== true) {
+      return;
+    }
+
+    await Promise.all(recentAchievements.map(async(achievement) => {
+      await channel.send({
+        components: constructComponents(achievement),
+        flags:      [ MessageFlags.IsComponentsV2 ],
+      });
+    }));
+  } catch (error) {
+    if (error instanceof Error) {
+      await logger.error("checkRetroAchievements module", error);
+    }
+  }
 };