docs: add Build Small hackathon badges to README

Add Space metadata tags and a visible README badge section for Redac's Build Small Hackathon track, sponsor, and achievement claims.

Co-authored-by: OpenAI Codex <codex@openai.com>

README.md

@@ -10,8 +10,41 @@ app_file: app.py
 pinned: false
 license: other
 short_description: Redac
+tags:
+- track:backyard
+- sponsor:openai
+- sponsor:openbmb
+- achievement:offgrid
+models:
+- openbmb/MiniCPM-V-4_5
+- urchade/gliner_multi_pii-v1
 ---
 
 # Redac
 
-Minimal Gradio starter. Edit `app.py` to build out the app.
+Redac is a local privacy gateway: paste sensitive text or upload a document/ID
+image, extract and redact PII locally, then copy the safe output into any LLM
+without exposing raw personal data. The local placeholder map lets you rehydrate
+answers afterward.
+
+## Build Small Hackathon Badges
+
+| Badge | Why Redac qualifies |
+|---|---|
+| 🏡 **Backyard AI** (`track:backyard`) | Redac solves a practical privacy problem for people who want to use LLMs with medical, ID, banking, or personal documents without leaking raw PII. |
+| 🌀 **OpenAI Track** (`sponsor:openai`) | The Space history includes Codex-attributed commits, and the app is designed around a copy-safe workflow for downstream LLM use. |
+| 🏮 **OpenBMB Awards** (`sponsor:openbmb`) | Image extraction uses `openbmb/MiniCPM-V-4_5` in-Space via ZeroGPU before the extracted fields flow into the redaction core. |
+| 🔌 **Off the Grid** (`achievement:offgrid`) | Extraction, detection, redaction, and rehydration run inside the Space process. No external AI API receives raw PII. |
+
+## Models
+
+- `openbmb/MiniCPM-V-4_5` — local document/ID image extraction.
+- `urchade/gliner_multi_pii-v1` — local PII-tuned zero-shot NER.
+
+## Flow
+
+1. Paste text or upload a document image.
+2. Redac extracts fields locally when needed.
+3. Redac replaces detected PII with stable placeholders.
+4. Copy the safe output into your LLM.
+5. Rehydrate the LLM answer locally when you need the original values back.