Add manufacturer catalog, category/manufacturer library management, and built-in cable flag

Normalizes manufacturer as a shared catalog entity (like device categories)
instead of free text on each device, giving the admin duplicate-detection
nudge a reliable signal. Adds full CRUD (including Admin direct-publish,
bypassing the submission queue) for categories, manufacturers, port types,
and cable types, plus a Categories & Manufacturers library modal and a
browse-by-manufacturer/search view in the device palette. Adds
Port.builtInCable so a captive/permanently-attached cable (a keyboard's USB
lead, a budget AVR's power cord) can be flagged and excluded from the BOM.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017DUU6CnxECCDeqDNYJgr5x

supabase/migrations/20260919000000_built_in_cable.sql

@@ -0,0 +1,9 @@
+-- Devices with a captive/permanently-attached cable (a keyboard's USB
+-- cable, a budget AV receiver's power cord, some passive speakers' fixed
+-- speaker wire, ...) — a property of the physical port, not of any one
+-- wiring choice, so it lives on device_template_ports rather than on
+-- connections (which aren't even a relational table — see diagrams' JSONB
+-- `data` for those; nothing to migrate there, the domain type change alone
+-- covers newly-placed devices, and this column is what the palette/library
+-- side needs).
+alter table public.device_template_ports add column built_in_cable boolean not null default false;