feat: agent monitor characters, cast panel, WSL fixes, and Sonnet 4.6 (#149)

## Summary

### New Features
- **Claude Sonnet 4.6 support** — added `claude-sonnet-4-6` as a selectable model in the config sidebar
- **Anime girl characters for subagents** — each subagent in the agent monitor is automatically assigned one of six characters (Amari, Keiko, Minori, Reina, Tatsumi, Yumiko) with a unique name, CDN avatar, title, and lore-flavoured description; assignment avoids duplicates when possible
- **"Meet the Team" cast panel** — a new modal accessible from the status bar introduces the full cast: Naomi (Chief hEx-ecutive Officer), Hikari (Chief Operating Officer), and the six subagent girls with their C-suite titles and character bios

### Bug Fixes
- **"Already running" error on invalid working directory** — if a spawned Claude process exits unexpectedly (e.g. because the working directory doesn't exist), `try_wait()` now detects the stale handle and clears it before allowing a restart
- **Working directory pre-validation** — on Windows, the app now runs `wsl -e test -d <dir>` before launching Claude; invalid directories surface a clear error immediately
- **WSL binary detection** — on Windows, `wsl -e bash -lc "which claude"` is used to probe for the Claude binary inside WSL; on Linux/WSLg, `bash -lc "which claude"` is used as a login-shell fallback so GUI apps find the binary even without shell PATH
- **WSL detection fix for production builds** — `detect_wsl()` now short-circuits at compile time on Windows targets, preventing inherited `WSL_DISTRO_NAME` env vars from misrouting native Windows binaries through the Linux code path

✨ This PR was crafted with love by Hikari~ 🌸

Reviewed-on: #149
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/stores/agents.test.ts

@@ -2,12 +2,15 @@ import { describe, it, expect, beforeEach } from "vitest";
 import { agentStore, getAgentsForConversation, runningAgentCount } from "./agents";
 import { get } from "svelte/store";
 import type { AgentInfo } from "$lib/types/agents";
+import { CHARACTER_POOL } from "$lib/utils/agentCharacters";
 
 describe("agents store", () => {
   const conversationId = "test-conversation-1";
   const otherConversationId = "test-conversation-2";
 
-  const createMockAgent = (overrides?: Partial<AgentInfo>): AgentInfo => ({
+  type AgentInput = Omit<AgentInfo, "characterName" | "characterAvatar">;
+
+  const createMockAgent = (overrides?: Partial<AgentInput>): AgentInput => ({
     toolUseId: "toolu_test123",
     description: "Test agent",
     subagentType: "Explore",
@@ -37,7 +40,29 @@ describe("agents store", () => {
 
       const agents = get(getAgentsForConversation(conversationId));
       expect(agents).toHaveLength(1);
-      expect(agents[0]).toEqual(agent);
+      expect(agents[0]).toMatchObject(agent);
+    });
+
+    it("assigns a character name and avatar to added agents", () => {
+      const agent = createMockAgent();
+      agentStore.addAgent(conversationId, agent);
+
+      const agents = get(getAgentsForConversation(conversationId));
+      const validNames = CHARACTER_POOL.map((c) => c.name);
+      expect(validNames).toContain(agents[0].characterName);
+      expect(agents[0].characterAvatar).toMatch(/^https:\/\//u);
+    });
+
+    it("avoids duplicate character names across agents when possible", () => {
+      // Add 6 agents - each should ideally get a unique character
+      for (let i = 0; i < 6; i++) {
+        agentStore.addAgent(conversationId, createMockAgent({ toolUseId: `tool${i.toString()}` }));
+      }
+
+      const agents = get(getAgentsForConversation(conversationId));
+      const names = agents.map((a) => a.characterName);
+      const uniqueNames = new Set(names);
+      expect(uniqueNames.size).toBe(6);
     });
 
     it("adds multiple agents to the same conversation", () => {
@@ -49,8 +74,8 @@ describe("agents store", () => {
 
       const agents = get(getAgentsForConversation(conversationId));
       expect(agents).toHaveLength(2);
-      expect(agents[0]).toEqual(agent1);
-      expect(agents[1]).toEqual(agent2);
+      expect(agents[0]).toMatchObject(agent1);
+      expect(agents[1]).toMatchObject(agent2);
     });
 
     it("keeps agents in different conversations separate", () => {
@@ -65,8 +90,8 @@ describe("agents store", () => {
 
       expect(agents1).toHaveLength(1);
       expect(agents2).toHaveLength(1);
-      expect(agents1[0]).toEqual(agent1);
-      expect(agents2[0]).toEqual(agent2);
+      expect(agents1[0]).toMatchObject(agent1);
+      expect(agents2[0]).toMatchObject(agent2);
     });
   });
 
@@ -256,7 +281,7 @@ describe("agents store", () => {
 
       expect(agents1).toHaveLength(0);
       expect(agents2).toHaveLength(1);
-      expect(agents2[0]).toEqual(agent2);
+      expect(agents2[0]).toMatchObject(agent2);
     });
 
     it("does nothing if conversation doesn't exist", () => {

src/lib/stores/agents.ts

@@ -1,5 +1,6 @@
 import { writable, derived } from "svelte/store";
 import type { AgentInfo } from "$lib/types/agents";
+import { assignCharacter } from "$lib/utils/agentCharacters";
 
 // Map of conversation ID -> agents in that conversation
 const agentsByConversation = writable<Record<string, AgentInfo[]>>({});
@@ -8,12 +9,17 @@ function createAgentStore() {
   return {
     subscribe: agentsByConversation.subscribe,
 
-    addAgent(conversationId: string, agent: AgentInfo) {
+    addAgent(conversationId: string, agent: Omit<AgentInfo, "characterName" | "characterAvatar">) {
       agentsByConversation.update((state) => {
         const existing = state[conversationId] || [];
+        const activeNames = existing.map((a) => a.characterName);
+        const character = assignCharacter(activeNames);
         return {
           ...state,
-          [conversationId]: [...existing, agent],
+          [conversationId]: [
+            ...existing,
+            { ...agent, characterName: character.name, characterAvatar: character.avatar },
+          ],
         };
       });
     },

src/lib/stores/stats.ts

@@ -12,6 +12,7 @@ export type BudgetType = "token" | "cost";
 export const MODEL_PRICING: Record<string, { input: number; output: number }> = {
   // Current generation (Claude 4.6)
   "claude-opus-4-6": { input: 5.0, output: 25.0 },
+  "claude-sonnet-4-6": { input: 3.0, output: 15.0 },
   // Previous generation (Claude 4.5)
   "claude-opus-4-5-20251101": { input: 5.0, output: 25.0 },
   "claude-sonnet-4-5-20250929": { input: 3.0, output: 15.0 },