refactor: rename materia → beanflows throughout codebase

- Rename src/materia/ → src/beanflows/ (Python package)
- Rename transform/sqlmesh_materia/ → transform/sqlmesh_beanflows/
- Rename infra/supervisor/materia-supervisor.service → beanflows-supervisor.service
- Rename infra/backup/materia-backup.{service,timer} → beanflows-backup.{service,timer}
- Update all path strings: /opt/materia → /opt/beanflows, /data/materia → /data/beanflows
- Update pyproject.toml: project name, CLI entrypoint, workspace source key
- Update all internal imports from materia.* → beanflows.*
- Update infra scripts: REPO_DIR, service names, systemctl references
- Fix docker-compose.prod.yml: /data/materia → /data/beanflows (bind mount path)

Intentionally left unchanged: Pulumi stack name (materia-infrastructure) and
Hetzner resource names ("materia-key", "managed_by: materia") — these reference
live cloud infrastructure and require separate cloud-side renames.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

transform/sqlmesh_beanflows/seeds/commodity_exchange_codes.csv

@@ -0,0 +1,57 @@
+commodity_name,exchange_code,exchange
+Crude Oil WTI,CL,CME
+Crude Oil Brent,BZ,ICE
+Gasoline RBOB,RB,CME
+Heating Oil,HO,CME
+Natural Gas,NG,CME
+Ethanol,CU,CME
+Cocoa,CC,ICE
+Cotton,CT,ICE
+Orange Juice,FCOJ-A,ICE
+Coffee,KC,ICE
+Lumber,LBR,ICE
+Sugar,SB,ICE
+European Gas TTF,TTF,ICE
+European Union Emissions Allowance,ECF,ICE
+Gold,GC,CME
+Silver,SI,CME
+Platinum,PL,CME
+Copper,HG,CME
+Palladium,PA,CME
+Live Cattle,LE,CME
+Feeder Cattle,GF,CME
+Lean Hogs,HE,CME
+Corn,ZC,CME
+Soybean Oil,ZL,CME
+Soybean meal,ZM,CME
+Oats,ZO,CME
+Rough Rice,ZR,CME
+Soybeans,ZS,CME
+Wheat,ZW,CME
+Canola,RS,ICE
+Rebar,RB,SHFE
+Hot-Rolled Coil,HC,SHFE
+Nickel,NI,SHFE
+Tin,SN,SHFE
+Aluminum,AL,SHFE
+Zinc,ZN,SHFE
+Natural Rubber,RU,SHFE
+Bitumen,BU,SHFE
+Iron Ore,I,DCE
+Palm Oil,P,DCE
+Eggs,JD,DCE
+Coking Coal,JM,DCE
+Polyvinyl Chloride (PVC),V,DCE
+White Sugar,SR,ZCE
+Cotton,CF,ZCE
+Apple,AP,ZCE
+PTA,TA,ZCE
+Methanol,MA,ZCE
+LME Aluminum,AH,LME
+LME Copper,CA,LME
+LME Lead,PB,LME
+LME Nickel,NI,LME
+LME Tin,SN,LME
+LME Zinc,ZS,LME
+Iron Ore,TIO,SGX
+Rubber,TSR,SGX