Add Hugging Face Spaces deploy config (free hosting)

- README frontmatter: sdk=docker, app_port=8000 (HF Space config)
- Dockerfile: chmod 777 /data so it's writable under HF's container user
- DEPLOY.md: Hugging Face Spaces steps (free) as the primary path, Render as paid alt

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

DEPLOY.md

@@ -1,9 +1,37 @@
-# Deploying to the cloud (Render)
+# Deploying
 
 The app is packaged as a **single Docker image**: it builds the React frontend and
-serves it together with the FastAPI API on one port. A `render.yaml` blueprint
-deploys it as one web service with a **persistent disk** (so projects, captures, and
-uploaded images survive restarts and redeploys).
+serves it together with the FastAPI API on one port (8000).
+
+## Option A — Hugging Face Spaces (free) ⭐ recommended for a demo
+
+Free, permanent public URL, no credit card. The repo root already has the Space
+config (the YAML block at the top of `README.md`: `sdk: docker`, `app_port: 8000`).
+
+1. Create a free account at https://huggingface.co.
+2. **New → Space**: choose **Docker** SDK (blank template), name it, set visibility
+   (Public = your boss can open the link with no login).
+3. Push this repo to the Space's git remote (replace `<user>`/`<space>`):
+   ```bash
+   git remote add space https://huggingface.co/spaces/<user>/<space>
+   git push space main
+   ```
+   (Authenticate with an HF access token from https://huggingface.co/settings/tokens
+   — username = your HF name, password = the token.)
+4. In the Space → **Settings → Variables and secrets** → add a **secret**
+   `GEMINI_API_KEY` = your paid key. (The model names default in code; no need to set
+   them.)
+5. The Space builds (~3–5 min) and serves at `https://<user>-<space>.hf.space`.
+
+**Free-tier caveat:** storage is **ephemeral** — projects/captures/uploads reset when
+the Space rebuilds or is restarted (fine for a demo; data is intact during a session).
+The Space sleeps after long inactivity and wakes on the next visit. Gemini is still
+billed per comparison.
+
+## Option B — Render (persistent, paid)
+
+Deploys via the `render.yaml` blueprint as one web service with a **persistent disk**
+(projects, captures, and uploaded images survive restarts and redeploys).
 
 ## One-time setup
 

Dockerfile

@@ -19,9 +19,11 @@ COPY demo1-physical-cad/backend/ ./
 # built SPA -> ./static (served by app.py when present)
 COPY --from=frontend /fe/dist ./static
 
-# uploads + SQLite live here; mount a persistent disk at /data in the cloud
+# uploads + SQLite live here; mount a persistent disk at /data in the cloud.
+# world-writable so it works whether the host runs the container as root or a
+# non-root user (e.g. Hugging Face Spaces).
 ENV LIVE_DATA_DIR=/data
-RUN mkdir -p /data
+RUN mkdir -p /data && chmod 777 /data
 
 EXPOSE 8000
 CMD ["sh", "-c", "uvicorn app:app --host 0.0.0.0 --port ${PORT:-8000}"]

README.md

@@ -1,3 +1,16 @@
+---
+title: DevisionX Progress Tracking
+emoji: 🏗️
+colorFrom: blue
+colorTo: gray
+sdk: docker
+app_port: 8000
+pinned: false
+---
+
+<!-- The block above configures Hugging Face Spaces (Docker SDK). It is ignored by
+     GitHub except as a small metadata table. See DEPLOY.md for deploy steps. -->
+
 # DevisionX — Site Progress Tracking (Physical → CAD)
 
 An on-premise tool that tracks **construction progress** by comparing site photos