Build this tool: Challenge Series Namer - Consistent Branding for Recurring Food/Stunt Challenges
Product folder name: Challenge Series Namer

PRODUCT BRIEF
Generator that takes a challenge concept and outputs a consistent naming convention (Challenge #, emoji set, hashtag block) reusable across future videos in the series.

CONTEXT
Difficulty: Easy
Category: Howto & Style

TREND HOOK
Smores, Cheetos, waterpark rule-breaking, soda-making — repeatable challenge-style content without series branding.

VIDEO ANGLE
Short: "Your challenge videos need a naming system — here's mine." Long: apply it to a mock 5-part challenge series.

WHY THIS TOOL
New niche (challenge branding) distinct from shipped Franchise Namer (multi-channel) — this is single-series naming.

STACK (standalone desktop app)
- Python 3 + tkinter GUI — standalone desktop tool (not a website).
- Even if the brief says "web app" / "site", ship a Python desktop GUI for v1.
- Include: main .py, requirements.txt, run_*.bat, build_exe.bat (PyInstaller), and an exports/ folder for saved output.
- Smoke-test core logic offline without requiring live API keys when possible.

GUI RULES
- Clean, readable dark or light UI — pick one consistent palette (no brand lock-in required).
- Clear app title / hero name derived from the product folder name.
- Short muted "How to use: …" line under the title (one sentence: what to enter → what button → what you get).
- Prefer real inputs (paste URL / fields / text) over fake demos.
- No sample dropdowns or canned demo datasets unless explicitly requested.
- Dropdowns: NEVER ttk.Combobox (unreadable on Windows dark UI). Use DarkSelect
  (preferred, no grab_set) OR dark-styled tk.OptionMenu (BG_ELEVATED / TEXT /
  active #243056 / BORDER+TEAL highlight; style the popup menu the same way).
  Never use grab_set (breaks close behavior on Windows).
- Handle window close with WM_DELETE_WINDOW.
- One job per tool; working copy/export; avoid overbuilt dashboards.

APIs & KEYS
- Never hardcode API keys or secrets into source or the packaged EXE.
- Store keys in a local user settings JSON under %LOCALAPPDATA%\<AppName>\ (or a single shared settings file if multiple tools share a key).
- Label each key field clearly in the UI (e.g. YouTube API key vs Gemini API key).
- Local/offline logic must work first; APIs are optional enhancements where possible.
- Call network APIs in a background thread; update the UI with after(...). On failure, keep local results and show a clear error.

Gemini API (AI-first copy)
- Add Gemini (AI-first for paste-ready copy) when the tool WRITES language creators will paste online
  (titles, captions, descriptions, pinned comments, end-cards, disclaimers, SEO templates).
- UI: API key field + Model text field + checkbox like "Write with Gemini (recommended)".
- Default model: gemini-2.5-flash-lite. Also accept typed model ids (e.g. gemini-3.1-flash-lite).
- Do not hardcode the model URL/path; pass the Model field value into the generate call.
- Pattern: Gemini writes the naming pack first (unique episode hooks under one series pattern).
  Local templates are fallback if Gemini is off/fails.
- On Gemini failure: keep local output, show error, do not wipe results.
- Flash Lite is enough for short creative jobs — do not default to Pro.

IMPLEMENTATION NOTES
- Match the product brief closely; keep v1 focused on one job.
- Support Copy and/or Export of results where useful (TXT/CSV/JSON as fits the tool).
- Validate inputs; show empty/error states clearly.
- If scoring/grading: show score + short explanation of what failed/passed.
- If generating copy: show multiple variants when the brief asks for them.

DEMO INPUT → OUTPUT (from live scan)
- Field Challenge Concept: water gun shoot out
- Field Series Name: Casey Builds It
- Field Title Pattern: Challenge #N - Concept
- Field Emoji Style: Fire / Hype
- Primary button: Generate naming pack
- Example result lines (MUST be unique hooks):
  RESULT #1 | 🔥 Challenge #1 - water gun shoot out (No Cover)
  RESULT #2 | ⚡ Challenge #2 - water gun shoot out (Blindfolded)
  RESULT #3 | 💥 Challenge #3 - water gun shoot out (Team vs Team)
  RESULT #4 | 🚀 Challenge #4 - water gun shoot out (One Life)
  RESULT #5 | 😤 Challenge #5 - water gun shoot out (Finals)
- Result Hashtags: #challenge #challengeseries #letsplay #gaming #youtube #shorts

OUTPUT
- Runnable standalone Python app
- requirements.txt + run bat + optional EXE build script
- In-app how-to line
- Example of typical input → output (in README or comments, not fake UI samples)