test: remove junk tests that assert source text instead of behavior (#23815)

Deletes 101 test files and trims 112 more, all matching documented junk
patterns: exact source/import/string greps, copied inventories and export
lists, duplicate invocations of a contract another test already owns,
typeof-shape checks TypeScript already enforces, and self-comparisons.

The largest group read a production `.ts` file and asserted on its text —
for example a TaskPage test that required the source to contain
`selectedRepos.find((r) => r.id === newIssueRepoId) ?? selectedRepos[0] ?? null`.
Any behavior-preserving rename broke it; no behavior change ever did.

Production-side follow-through: exports that only these tests imported are
de-exported or deleted, stale comments pointing at removed censuses are
dropped, and the reliability-gate registry, `cloud/package.json` test lists,
and orphaned source-reading helpers are updated so nothing references a
deleted file.

Two files kept their real coverage and lost only the census scaffolding:
`agent-status-producer-census.test.ts` now drives all five producers end to
end instead of grepping the source tree, and `config-toml-trust-stale-writes`
replaces an export-list parity check.

src/main/github/work-item-details-api-parity.test.ts

@@ -1,37 +0,0 @@
-import { describe, expect, expectTypeOf, it } from 'vitest'
-import type { GitHubPRFile, GitHubPRFileContents } from '../../shared/github/pull-request-types'
-import type { GitHubWorkItemDetails } from '../../shared/github/work-item-types'
-import type { IssueSourcePreference } from '../../shared/repo-types'
-import type { LocalGitExecOptions } from './gh-utils'
-import type { GitHubApiRepository } from './github-api-repository'
-import * as workItemDetails from './work-item-details'
-
-type GetWorkItemDetails = (
-  repoPath: string,
-  number: number,
-  type?: 'issue' | 'pr',
-  connectionId?: string | null,
-  localGitOptions?: LocalGitExecOptions,
-  preference?: IssueSourcePreference
-) => Promise<GitHubWorkItemDetails | null>
-
-type GetPRFileContents = (args: {
-  repoPath: string
-  connectionId?: string | null
-  localGitOptions?: LocalGitExecOptions
-  prRepo?: GitHubApiRepository | null
-  prNumber: number
-  path: string
-  oldPath?: string
-  status: GitHubPRFile['status']
-  headSha: string
-  baseSha: string
-}) => Promise<GitHubPRFileContents>
-
-describe('work-item-details public API parity', () => {
-  it('retains only the established runtime exports and call signatures', () => {
-    expect(Object.keys(workItemDetails).sort()).toEqual(['getPRFileContents', 'getWorkItemDetails'])
-    expectTypeOf(workItemDetails.getWorkItemDetails).toEqualTypeOf<GetWorkItemDetails>()
-    expectTypeOf(workItemDetails.getPRFileContents).toEqualTypeOf<GetPRFileContents>()
-  })
-})