Refactor code structure for improved readability and maintainability

.env.example

@@ -13,7 +13,23 @@
 # NOT required to run the app: object detection, faces, OCR, and Remove Background
 # all run FREE in-browser with no key. Full guide: docs/AI-SETUP.md
 # ---------------------------------------------------------------------------
-# AI_EDIT_PROVIDER=auto            # auto | local | huggingface | gemini | none
+# AI_EDIT_PROVIDER=auto            # auto | runpod | local | huggingface | gemini | none
+#
+# Option 0 — RunPod serverless GPU endpoints (one per model; key stays server-side).
+# `auto` picks this first when RUNPOD_API_KEY + an SD URL are set. Deploy endpoints so
+# their URLs end in /runsync. Full map (op → endpoint) in docs/AI-SETUP.md.
+# AI_EDIT_PROVIDER=runpod
+# RUNPOD_API_KEY=rpa_xxxxxxxx
+# RUNPOD_SD_IMG2IMG_URL=https://api.runpod.ai/v2/<id>/runsync   # #10 prompt (img2img)
+# RUNPOD_SD_INPAINT_URL=https://api.runpod.ai/v2/<id>/runsync   # #9  replace-sky / magic-eraser / generative-fill (masked)
+# RUNPOD_UPSCALE_URL=https://api.runpod.ai/v2/<id>/runsync      # #7  restore / upscale (Real-ESRGAN)
+# RUNPOD_COLORIZE_URL=https://api.runpod.ai/v2/<id>/runsync     # #8  colorize (DDColor)
+# RUNPOD_BG_REMOVE_URL=https://api.runpod.ai/v2/<id>/runsync    # #6  (optional; default is in-browser @imgly)
+# RUNPOD_YOLO_URL=https://api.runpod.ai/v2/<id>/runsync         # #1  detection (needs the flag below)
+# NEXT_PUBLIC_APG_RUNPOD_DETECT=false   # true = use #1 YOLO server detection (else free in-browser COCO-SSD)
+# Optional SD tuning: RUNPOD_SD_STEPS RUNPOD_SD_STRENGTH RUNPOD_SD_GUIDANCE RUNPOD_SD_NEGATIVE_PROMPT
+# Scaffold-only (typed client, no route/UI yet): RUNPOD_TILT_URL (#2) RUNPOD_STT_URL (#3)
+#   RUNPOD_AUDIO_DENOISE_URL (#12) RUNPOD_VIDEO_FPS_URL (#13) RUNPOD_VIDEO_UPSCALE_URL (#14)
 #
 # Option 1 — your own local Stable Diffusion (AUTOMATIC1111/Forge/SD.Next; free + private):
 # LOCAL_SD_URL=http://127.0.0.1:7860