Make material links inspectable and directly editable

[ApocDev]

Problem

Block routing constraints are still exposed primarily through recipe-row pins. The all-surplus route marker is visible and opens the Pins dialog, but there is no good-level view of the complete link: which rows produce it, which rows consume it, their totals, and whether surplus is allowed.

YAFC-CE treats a material link as first-class sheet state. Its good interaction can link/unlink directly, toggle allowed overproduction, and open a summary of every producer and consumer. PyOps has stronger solver provenance and flow views, but this basic inspection/editing surface would make routing state easier to understand and repair.

Proposed surface

• Open a link inspector from a linked good or route marker.
• List every producing and consuming row with localized names and solved rates.
• Show total production, total consumption, requested flow, and remaining surplus/shortfall.
• Provide direct link/unlink and allow-surplus controls at the good level.
• Keep recipe share pins available for explicit fan-out; do not collapse them into the good-level link.
• Reuse existing drain/made constraints and IIS actions rather than adding a second solver model.

Acceptance

• Feedback recyclers, terminal sinks, and multiple consumers are all represented accurately.
• The inspector is reachable without discovering the recipe-row context menu.
• Link/unlink changes are undoable and covered by mutating browser tests.
• User and solver documentation describe the visible controls and constraint semantics.