chore: Add .env.example template for backend local dev

.env.example

@@ -0,0 +1,70 @@
+# Copy this to .env and fill in your real keys
+# NEVER commit .env — it contains secrets!
+
+# ── Database ──
+DATABASE_URL=postgres://courtmitra:courtmitra@localhost:5432/courtmitra
+DIRECT_DATABASE_URL=postgres://courtmitra:courtmitra@localhost:5432/courtmitra
+
+# ── App URLs ──
+APP_BASE_URL=http://localhost:3000
+API_BASE_URL=http://localhost:3001
+WEBHOOK_BASE_URL=http://localhost:3001
+
+# ── AI Provider ──
+# Options: openrouter | opencode
+AI_PROVIDER=openrouter
+OPENROUTER_API_KEY=
+AI_MODEL=google/gemini-2.0-flash-exp:free
+AI_VISION_MODEL=google/gemini-2.0-flash-exp:free
+
+# ── OpenCode (alternative AI provider) ──
+# OPENCODE_API_KEY=
+# OPENCODE_BASE_URL=https://opencode.ai/zen/go/v1
+# AI_MODEL=deepseek-v4-flash
+# AI_VISION_MODEL=qwen3.6-plus
+
+# ── Clerk (backend JWT verification) ──
+CLERK_SECRET_KEY=
+# Optional: for networkless JWT verification
+# CLERK_JWT_KEY=
+# CLERK_AUTHORIZED_PARTIES=http://localhost:3000
+
+# ── Local Dev Mode ──
+# DEMO_MODE=true
+
+# ── Object Storage (optional — evidence files) ──
+# OBJECT_STORAGE_ENDPOINT=
+# OBJECT_STORAGE_BUCKET=
+# OBJECT_STORAGE_ACCESS_KEY=
+# OBJECT_STORAGE_SECRET_KEY=
+
+# ── Email (Resend) ──
+# RESEND_API_KEY=
+# RESEND_FROM=noreply@example.com
+
+# ── Inngest (background workflows) ──
+# INNGEST_EVENT_KEY=
+# INNGEST_SIGNING_KEY=
+INNGEST_BASE_URL=http://localhost:8288
+INNGEST_DEV=1
+
+# ── Secrets ──
+JWT_SECRET=dev-jwt-secret-change-me-32-chars!!
+PII_HASH_SALT=dev-salt-change-me
+TOKEN_ENCRYPTION_KEY=dev-enc-key-min-32-chars!!
+
+# ── Observability ──
+# LANGFUSE_PUBLIC_KEY=
+# LANGFUSE_SECRET_KEY=
+
+# ── Qdrant (Phase 2) ──
+# QDRANT_URL=
+# QDRANT_API_KEY=
+# QDRANT_COLLECTION=courtmitra_legal
+
+# ── Other optional keys ──
+# OPENAI_API_KEY=
+# BROWSERBASE_API_KEY=
+# BROWSERBASE_PROJECT_ID=
+# SUREPASS_API_KEY=
+# ENABLE_PORTAL_AUTOMATION=