Plan the overhead crane, maintenance workshop and visitor corridor

New docs/crane-workshop-tours.md: a 5 t single-girder EOT crane over the
whole production compartment (stops at the warehouse fire wall), a
machine door and crane-served workshop/machine bay at the ramp end, and
a glazed ground-level visitor corridor along the car-park elevation with
stations in process order, its own air and acoustic glazing so tours
need no PPE. Covers what each changes in the shell (crane-ready frame,
hook height under the 7.0 m eave, no full-height cross walls in the
crane zone, room lids and crane hatches), safety, costs and open
decisions.

Propagated: construction RFQ (crane-ready frame, new section 1c, machine
door, accessible 1:12 entrance now required), scale zone table (+210 to
280 m2, total ~1,400 to 2,000 m2), facility security, worker safety,
roadmap items 9 and 15, total investment added-scope table, README.

docs/worker-safety.md

@@ -16,6 +16,15 @@ commitments:
   goggles, and process-specific protection) is mandatory per work area, in
   line with the equipment vendor's site requirements (exhaust work benches,
   fire protection) and local regulations.
+- **Lifting and machine service**: the overhead crane needs trained
+  operators and slingers, a lift plan for every machine move, and the
+  periodic engineer inspections Thai law sets for cranes. A machine is
+  only disconnected and lifted after lockout: electrical isolation, steam
+  vented, hydraulics depressurised including the accumulator. Welding and
+  grinding stay in the workshop's hot-work corner under a permit. Detail
+  in [crane, workshop and tours](crane-workshop-tours.md).
+- **Visitors** never share the floor's hazards: tours run in a glazed
+  corridor with its own air and no PPE requirement.
 
 Safety infrastructure (training program, clean-room specification,
 decontamination workflow) will be planned alongside the equipment, not after