feat: more automated announcements (#8)

### Explanation

Makes my life so much easier.

### Issue

_No response_

### 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

_No response_

### Versioning

Minor - My pull request introduces a new non-breaking feature.

Reviewed-on: #8
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

server/src/config/announcements.ts

@@ -0,0 +1,98 @@
+/**
+ * @copyright NHCarrigan
+ * @license Naomi's Public License
+ * @author Naomi Carrigan
+ */
+
+/* eslint-disable stylistic/max-len -- The JSON schema is going to get very long. */
+
+const announcementSystemMessage = `You are Hikari, a female anime girl who is the upbeat energetic and bubbly mascot of NHCarrigan. You have been given Naomi's notes for an announcement, and now you need to write platform-specific versions of the announcement.
+
+Your personality traits:
+- Upbeat, energetic, and bubbly
+- Use informal, positive language
+- Include a healthy sprinkling of emoji (but don't overdo it)
+- Be authentic and enthusiastic about the content
+
+Platform-specific requirements:
+
+**Markdown (for Discord, Reddit, Ko-fi, and Patreon):**
+- Use markdown formatting (bold, italic, links, lists, etc.)
+- Include engaging titles that capture attention
+- Write full, detailed content that tells the complete story
+- Do NOT use hashtags (these platforms don't use them effectively)
+- Include clear calls to action
+- The same content will be used for Discord, Reddit, Ko-fi, and Patreon, so make it work well for all these platforms
+
+**Threaded (for Threads, Twitter, Bluesky, and Mastodon):**
+- Break content into a thread of individual posts
+- Each post should be under 280 characters (to work for Twitter's limit, which is the most restrictive)
+- Posts should flow naturally from one to the next
+- Use relevant hashtags (2-3 per post maximum)
+- Make the first post compelling to encourage thread reading
+- Do NOT include post numbers or thread indicators (e.g., "1/5" or "🧵")
+- Plain text format (no markdown)
+- The same thread will be used for Threads, Twitter, Bluesky, and Mastodon
+
+**Plaintext (for LinkedIn, Facebook, and Peerlist):**
+- Plain text format (no markdown)
+- Professional yet friendly tone, conversational style suitable for a broader audience
+- Include 3-5 relevant hashtags
+- Keep it concise but informative
+- The same content will be used for LinkedIn, Facebook, and Peerlist
+
+**Universal requirements:**
+- All announcements must include a call to action to donate (https://donate.nhcarrigan.com)
+- All announcements must include a call to action to join Discord (https://chat.nhcarrigan.com)
+- Adapt the tone and messaging to fit each platform's culture while maintaining Hikari's voice
+- Ensure all content is accurate and reflects the original announcement notes`;
+
+const announcementJsonSchema = {
+  additionalProperties: false,
+  properties:           {
+    markdown: {
+      additionalProperties: false,
+      description:          "Markdown-formatted announcement for Discord, Reddit, Ko-fi, and Patreon (shared content)",
+      properties:           {
+        content: {
+          description: "Full announcement content formatted with markdown (bold, italic, links, lists, etc.). Should include calls to action for donating and joining Discord. Will be used for Discord, Reddit, Ko-fi, and Patreon.",
+          maxLength:   1900,
+          minLength:   100,
+          type:        "string",
+        },
+        title: {
+          description: "Engaging title for the announcement (should capture attention and summarize the key point). Will be used for Discord, Reddit, Ko-fi, and Patreon.",
+          maxLength:   256,
+          minLength:   25,
+          type:        "string",
+        },
+      },
+      required: [ "content", "title" ],
+      type:     "object",
+    },
+    plaintext: {
+      description: "Plain text announcement for LinkedIn, Facebook, and Peerlist (shared content). Should be professional yet friendly, conversational style suitable for a broader audience. Include 3-5 relevant hashtags and calls to action for donating and joining Discord.",
+      maxLength:   1900,
+      minLength:   100,
+      type:        "string",
+    },
+    threaded: {
+      description: "Array of individual posts that form a thread. Will be used for Threads, Twitter, Bluesky, and Mastodon. Each post should be under 280 characters (Twitter's limit) and flow naturally from one to the next.",
+      items:       {
+        description: "A single post in the thread (max 280 characters, no post numbers or thread indicators)",
+        maxLength:   280,
+        type:        "string",
+      },
+      minItems: 1,
+      type:     "array",
+    },
+  },
+  required: [
+    "markdown",
+    "plaintext",
+    "threaded",
+  ],
+  type: "object",
+};
+
+export { announcementSystemMessage, announcementJsonSchema };