feat: initial product prototype (#1)

### Explanation

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### Issue

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### Attestations

- [x] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [x] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [x] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [x] I have pinned the dependencies to a specific patch version.

### Style

- [x] I have run the linter and resolved any errors.
- [x] My pull request uses an appropriate title, matching the conventional commit standards.
- [x] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

### Documentation

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### Versioning

Major - My pull request introduces a breaking change.

Reviewed-on: #1
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/modules/proofread.ts

@@ -0,0 +1,44 @@
+/**
+ * @copyright nhcarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+import { MessageFlags, type ChatInputCommandInteraction } from "discord.js";
+import { personality } from "../config/personality.js";
+import { ai } from "../utils/ai.js";
+import { isSubscribed } from "../utils/isSubscribed.js";
+
+/**
+ * Accepts a text snippet from the user. Submits it to Anthropic
+ * to be proofread for spelling and grammatical errors.
+ * @param interaction -- The interaction payload from Discord.
+ */
+export const proofread = async(
+  interaction: ChatInputCommandInteraction,
+): Promise<void> => {
+  await interaction.deferReply({ flags: [ MessageFlags.Ephemeral ] });
+  const sub = await isSubscribed(interaction);
+  if (!sub) {
+    return;
+  }
+
+  const prompt = interaction.options.getString("text", true);
+
+  const messages = await ai.messages.create({
+    // eslint-disable-next-line @typescript-eslint/naming-convention -- Required key format for SDK.
+    max_tokens:  2000,
+    messages:    [ { content: prompt, role: "user" } ],
+    model:       "claude-3-5-sonnet-latest",
+    system:      `${personality} Your role in this conversation is to proofread the text the user has provided. You should identify spelling and grammatical errors using British English.`,
+    temperature: 1,
+  });
+
+  const response = messages.content.find((message) => {
+    return message.type === "text";
+  });
+
+  await interaction.editReply(
+    response?.text
+      ?? "I'm sorry, I don't have an answer for that. Please try again later.",
+  );
+};