Flowntier v0.4.5 — NSIS install conflict + MiniMax form

What changed in v0.4.5

Two real fixes from chairman's hands-on testing:

• BUG-FRONTEND-RT-11 — NSIS installer error: 'Cannot open file: O:\Flowntier\flowntier_runtime.exe'. The previous v0.4.x install put files at O:\Flowntier\ and a running instance was locking the sidecar binary. Fix: added apps/desktop/src-tauri/nsis/installer.nsi with a customOnInit hook (Tauri's documented extension point) that uses Win32 Toolhelp32 (built into Windows since XP, no extra plugin dep) to detect a running flowntier.exe and shows a topmost MessageBox asking the user to close it before continuing the install.

• BUG-FRONTEND-RT-12 — MiniMax provider form overhaul: the chairman asked 'let the user fill in the model name + context length (free text), and pick thinking strength from a list'. Replaced the single ModelRow {id, display_name} with {id, display_name, context_length: number|null, thinking_strength: 'low'|'medium'|'high'}. New 'Models' form has 4 inline fields per row (id / name / context / thinking) + 1-line hint. context_length validated as a positive int ≤10M. thinking_strength is a <select> with low/medium/high options. Updated ProviderModel type in apps/desktop/src/lib/api.ts and 9 new i18n keys in each locale.

SECURITY reminder (not a code change)

An API key was pasted into the chat during testing. The key was not stored, logged, or transmitted anywhere by this agent, but the key should be rotated via the provider's console ASAP and stored only in environment variables or .env files (which should be in .gitignore). Plaintext API keys in chat logs are a real risk.