feat: add chat modes and interrupt feature (#46)

### Explanation

_No response_

### Issue

Closes #40

### Attestations

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

### Dependencies

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

### Style

- [ ] I have run the linter and resolved any errors.
- [ ] My pull request uses an appropriate title, matching the conventional commit standards.
- [ ] 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

_No response_

Reviewed-on: #46
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/types/messageMode.ts

@@ -0,0 +1,69 @@
+export interface MessageMode {
+  id: string;
+  name: string;
+  description: string;
+  prefix?: string;
+  icon: string;
+}
+
+export const MESSAGE_MODES: MessageMode[] = [
+  {
+    id: "chat",
+    name: "Chat",
+    description: "Normal conversation mode",
+    icon: "💬",
+  },
+  {
+    id: "architect",
+    name: "Architect",
+    description: "High-level design and architecture planning",
+    prefix: "[Architect Mode] ",
+    icon: "🏗️",
+  },
+  {
+    id: "code",
+    name: "Code",
+    description: "Focused on writing and editing code",
+    prefix: "[Code Mode] ",
+    icon: "💻",
+  },
+  {
+    id: "debug",
+    name: "Debug",
+    description: "Help with debugging and troubleshooting",
+    prefix: "[Debug Mode] ",
+    icon: "🐛",
+  },
+  {
+    id: "ask",
+    name: "Ask",
+    description: "Technical questions and explanations",
+    prefix: "[Ask Mode] ",
+    icon: "❓",
+  },
+  {
+    id: "review",
+    name: "Review",
+    description: "Code review and feedback",
+    prefix: "[Review Mode] ",
+    icon: "👀",
+  },
+];
+
+export function getMessageMode(id: string): MessageMode | undefined {
+  return MESSAGE_MODES.find((mode) => mode.id === id);
+}
+
+export function formatMessageWithMode(message: string, modeId: string): string {
+  const mode = getMessageMode(modeId);
+  if (!mode || !mode.prefix) {
+    return message;
+  }
+
+  // Don't double-prefix if the message already starts with the prefix
+  if (message.startsWith(mode.prefix)) {
+    return message;
+  }
+
+  return mode.prefix + message;
+}