feat: rename RootConnectionAuth for Backstage 1.54.0

[schultzp2020]

Summary

 import type {
-  RootConnectionAuth
+  ConfiguredConnectionAuth
 } from '@backstage/connections';
-type Auth = RootConnectionAuth<MyMethod>;
+type Auth = ConfiguredConnectionAuth<MyMethod>;

AST provenance limits edits to the Connections binding; aliases, generic arguments, re-exports, inline import types, and namespace members are covered. Unaliased re-exports deduplicate across statements; removed declarations preserve inline comments. /config remains a 1.55 migration. Minor changeset. Closes #145.

Evidence

• Before: four new fixtures failed on ec94018: as/satisfies inline import types remained stale; alias plus unaliased import/export duplicated ConfiguredConnectionAuth; removing sole //-commented export swallowed next inline statement.
  After (44e7216, b877ad7): 25/25 package fixtures pass, including generic constraints and EOF line-comment preservation. Runtime import expressions, /config, and foreign sources remain unchanged. AST-bound references preserve aliases; removed statements retain comments and terminating newline. Workflow validates with base_path: '.'.
• At 32a67da, yarn format, yarn format:check, yarn lint, yarn test, yarn check:changed, package yarn test, and git diff --check pass locally. Workflow dry-runs completed on the 25 input and expected fixtures; JSSG dry-run changed 24/25 inputs and made zero changes to 25/25 expected fixtures (0.054s). Earlier representative dry-runs: no-op 0.013s, real assertion migration 0.014s (single-run timings, not a benchmark).
• Package README (32a67da) documents source-qualified scope, exclusions, Yarn dlx preview/apply, and development checks. yarn dlx codemod@latest run --help confirms --target and --dry-run; minor changeset included.
• Earlier ec94018 workflow on 503-file mostly inert corpus (including excluded dist/): 2.07s vs same-entry no-op 1.96s; two files matched. Clean Backstage QA checkout 0863f0349c63 workflow dry-run: 4.2s; zero RootConnectionAuth TS/TSX matches, zero expected edits; checkout stayed clean.

Merge Danger

Door: two-way

Revert restores the prior codemod; no release or publication performed by this PR.

Blast Radius: type-imports

Only matched @backstage/connections type bindings and their references change. Review aliases, namespace cases, and inline import types in migrated consumers.