Key the duplicate-host refusal on host and tier #384

Parent

Rewrite the spec and the compiler in place, release 1.0.0, and hand over every Project

What to build

An Application author may put one hostname on two tiers, the split-horizon shape the media hosts, hermes and agents-ws already use. The same host twice on one tier is still refused, because inside one proxy the two rules have no defined winner. Settled in Decide how the model meets the live needs no chapter covers (item 1). It widens what the build accepts. Makes ready, with the step 5 concepts: media.

Acceptance criteria

• Two exposures with one host on two tiers compose and render one route per tier.
• Two exposures with one host on one tier are refused with E_DUPLICATE_HOST.
• The chapter states the rule and its refusals, with short rationale only, and CONTEXT.md carries each new term in the same pull request.
• A worked example shows it; its resolved artifact and its rendered tree are updated and reviewed by hand, never regenerated in CI.
• Each refusal has a refusal example with its diagnostics file.
• The JSON Schemas and their corpus admit the new shape and refuse a malformed one.
• The behaviour-ledger row lands with its test, and npm run verify passes.

Blocked by

• Split the compiler's mixed modules by concept, with no change of behaviour