Link references by name and report those that do not resolve #39

Parent

#35

What to build

References in Project Intent are typed references in the domain model, not strings: a route's Process and surface, a scrape's Process and surface, a dependency edge's Application and surface, and an ${exposure:...} placeholder's Application and exposure name. One linking step resolves them after parsing.

• References inside one document (routes, scrapes) resolve here. E_UNKNOWN_SURFACE fires when a route or scrape names a surface its Process does not provide, and the diagnostic carries the route's document path.
• References to another Application are recorded unresolved and resolved over the composed union by Evaluate identity and reference invariants over a composed union #46.
• Chapter 10 states one opt-out convention: where an absent block means "none" (an omitted observability block means no monitoring) and where an explicit none is required (probes, because a forgotten probe block is more dangerous than a forgotten alert). The metamodel encodes it.
• Chapter 10's class diagram draws the references as associations instead of dependency arrows labelled "resolves by name".

Parity

References become typed references in both implementations: domain types in src/, and Ecore references (not string attributes) in the Java Project Intent metamodel, which the descriptor records as references so the two cannot silently differ. E_UNKNOWN_SURFACE and the scrape code each get a refusal fixture with a committed diagnostics.json whose path is the JSON Pointer of the route or scrape. The Java counterpart is a Complete OCL invariant named by each code, filed with the Java Task 1 work.

Acceptance criteria

• A route naming a surface its Process does not provide fails with E_UNKNOWN_SURFACE and the route's path, proved by a refusal fixture.
• A scrape naming a Process outside its Application fails with a code.
• The domain types hold references to Processes and surfaces, not name strings.
• The opt-out convention is stated once in chapter 10.
• The descriptor records every reference as a reference with its target class, and both refusal fixtures carry committed diagnostics.

Blocked by

• Declare the Project Intent metamodel once and parse every example with it #38