refactor: companion FrameServer and related (substantive only, no Black)

Reapply refactor from ce8381a (replace monolithic FrameServer with thin
pymc_core subclass, re-export constants, SQLite persistence hooks) while
preserving pre-refactor whitespace where patch applied cleanly. Remaining
files match refactor commit exactly. Diff vs ce8381a is whitespace-only.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/build-prod.sh

@@ -152,7 +152,7 @@ if [ -n "$DEB_FILE" ]; then
     # Run lintian to check package quality
     log_step "Running lintian checks..."
     lintian "$DEB_FILE" || log_warn "Lintian found some issues (non-fatal)"
-    
+
     log_info ""
     log_info "════════════════════════════════════════════════════════════"
     log_info "Production build complete!"

scripts/setup-build-env.sh

@@ -23,7 +23,7 @@ log_error() {
 }
 
 # Check if running as root or with sudo
-if [ "$EUID" -ne 0 ]; then 
+if [ "$EUID" -ne 0 ]; then
     log_error "This script must be run with sudo or as root"
     exit 1
 fi