feat: Thread optional `phase` param into `db/sessions.ts::cre… (+7 more)

- ✅ Thread optional `phase` param into `db/sessions.ts::createSession()`
- ✅ Thread optional `phase` param into `ipc/handlers.ts` sessions:create handler
- ✅ Thread optional `phase` param into `preload.ts` createSession API
- ✅ Update Plan phase system prompt to gracefully handle missing research.md
- ✅ Update Implement phase system prompt to gracefully handle missing plan.md
- ✅ Create `renderer/src/components/NewSessionModal.tsx`
- ✅ Update `App.tsx`: add modal state, split handler, add modal JSX
- ✅ Add modal CSS to `globals.css`

1 files changed, 3 insertions, 3 deletions

diff --git a/src/main/ipc/handlers.ts b/src/main/ipc/handlers.ts
index 4894e1d..975ad01 100644
--- a/src/main/ipc/handlers.ts
+++ b/src/main/ipc/handlers.ts
@@ -5,7 +5,7 @@ import * as claude from "../claude";
 import * as settingsDb from "../db/settings";
 import { createSessionBranch, ensureGitIgnore, ensureGitRepo, getCurrentBranch } from "../git";
 import { discoverMcpTools } from "../mcp";
-import type { UserPermissionMode } from "../claude/phases";
+import type { UserPermissionMode, Phase } from "../claude/phases";
 import { getDefaultSystemPromptTemplate } from "../claude/phases";
 
 export function registerIpcHandlers(mainWindow: BrowserWindow): void {
@@ -23,11 +23,11 @@ export function registerIpcHandlers(mainWindow: BrowserWindow): void {
     sessions.listSessions(projectId)
   );
 
-  ipcMain.handle("sessions:create", (_, projectId: string, name: string) => {
+  ipcMain.handle("sessions:create", (_, projectId: string, name: string, phase?: Phase) => {
     const project = projects.getProject(projectId);
     if (!project) throw new Error("Project not found");
 
-    const session = sessions.createSession(projectId, name);
+    const session = sessions.createSession(projectId, name, phase);
 
     // Ensure .claude-flow/ is gitignored from day one.
     // Branch creation is deferred until the session advances to implement.