Rebrand SooSeF to FieldWitness

Complete project rebrand for better positioning in the press freedom
and digital security space. FieldWitness communicates both field
deployment and evidence testimony — appropriate for the target audience
of journalists, NGOs, and human rights organizations.

Rename mapping:
- soosef → fieldwitness (package, CLI, all imports)
- soosef.stegasoo → fieldwitness.stego
- soosef.verisoo → fieldwitness.attest
- ~/.soosef/ → ~/.fwmetadata/ (innocuous data dir name)
- SOOSEF_DATA_DIR → FIELDWITNESS_DATA_DIR
- SoosefConfig → FieldWitnessConfig
- SoosefError → FieldWitnessError

Also includes:
- License switch from MIT to GPL-3.0
- C2PA bridge module (Phase 0-2 MVP): cert.py, export.py, vendor_assertions.py
- README repositioned to lead with provenance/federation, stego backgrounded
- Threat model skeleton at docs/security/threat-model.md
- Planning docs: docs/planning/c2pa-integration.md, docs/planning/gtm-feasibility.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/Dockerfile

@@ -1,15 +1,9 @@
-# SooSeF Docker Image
-#
-# Requires stegasoo and verisoo source directories alongside soosef:
-#   Sources/
-#   ├── stegasoo/
-#   ├── verisoo/
-#   └── soosef/     ← build context is parent (Sources/)
+# FieldWitness Docker Image
 #
 # Build:
-#   docker build -t soosef -f soosef/docker/Dockerfile .
+#   docker build -t fieldwitness -f docker/Dockerfile .
 #
-# Or use docker-compose from soosef/docker/:
+# Or use docker-compose from docker/:
 #   docker compose up
 
 FROM python:3.12-slim
@@ -33,35 +27,21 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 WORKDIR /app
 
-# ── Install stegasoo ─────────────────────────────────────────────
-COPY stegasoo/pyproject.toml stegasoo/pyproject.toml
-COPY stegasoo/README.md stegasoo/README.md
-COPY stegasoo/src/ stegasoo/src/
-COPY stegasoo/data/ stegasoo/data/
-COPY stegasoo/frontends/ stegasoo/frontends/
-RUN pip install --no-cache-dir /app/stegasoo[web,dct,audio,cli]
-
-# ── Install verisoo ──────────────────────────────────────────────
-COPY verisoo/pyproject.toml verisoo/pyproject.toml
-COPY verisoo/README.md verisoo/README.md
-COPY verisoo/src/ verisoo/src/
-RUN pip install --no-cache-dir /app/verisoo[cli]
-
-# ── Install soosef ───────────────────────────────────────────────
-COPY soosef/pyproject.toml soosef/pyproject.toml
-COPY soosef/README.md soosef/README.md
-COPY soosef/src/ soosef/src/
-COPY soosef/frontends/ soosef/frontends/
-RUN pip install --no-cache-dir /app/soosef[web,cli]
+# ── Install fieldwitness ─────────────────────────────────────────
+COPY pyproject.toml pyproject.toml
+COPY README.md README.md
+COPY src/ src/
+COPY frontends/ frontends/
+RUN pip install --no-cache-dir /app[web,cli]
 
 # ── Runtime setup ────────────────────────────────────────────────
-RUN mkdir -p /root/.soosef
+RUN mkdir -p /root/.fwmetadata
 
-COPY soosef/docker/entrypoint.sh /app/entrypoint.sh
+COPY docker/entrypoint.sh /app/entrypoint.sh
 RUN chmod +x /app/entrypoint.sh
 
-ENV SOOSEF_DATA_DIR=/root/.soosef
-WORKDIR /app/soosef
+ENV FIELDWITNESS_DATA_DIR=/root/.fwmetadata
+WORKDIR /app
 
 EXPOSE 35811