Retire CI-059 terminal caller policy

[coenttb]

Summary

• retire CI-059, whose required secret inheritance contradicts the terminal credential-free caller architecture
• delete its validator branches, exemptions, messages, helpers, and fixture corpus
• retain CI-030, GH-REPO-074, and integrated-docs admission under their canonical Swift owner
• prove terminal callers are accepted in both layer and authority organizations
• adopt the byte-identical terminal zero-input caller in this repository

Evidence

• focused ThinCallers suite passed: 10 tests
• fresh complete package suite passed: 123 tests across 40 suites
• git diff --check passed
• exact off-machine PR and full tiers are attached to the current head

The initial exact-head runs were refused at admission because the incumbent caller still passed the deleted lint-bundle input. The current head removes that superseded caller input; it does not add compatibility to the reusable contract.

This removes a superseded migration checker; it does not weaken a live credential contract. Terminal package callers carry no credential surface, and the reusable owner remains responsible for its own bounded credentials.

Refs #7

[swift-institute-bot]

Independent transaction review: exact-head guards satisfied via the package profile; approval is not merge authorization.