refactor(integrations): split issue-tracker clients under the max-lines budget (#14704)

The GitLab, GitHub, Jira and Linear integration modules, their two IPC
registrars, and the shared GitHub project types each carried a file-level
`eslint-disable max-lines` and ran 351-614 counted lines against a 300-line
budget. AGENTS.md calls for splitting rather than suppressing, and
config/max-lines-baseline.txt is a shrink-only ratchet, so this removes all
eight suppressions and prunes their entries (341 -> 333).

Pure move, no behavior change. Each client is cut along the seam it already
had: per-operation modules for the issue APIs (create / update / comment /
field options), and for Jira the request queue, site credential store,
authenticated request, and site identity. The two IPC registrars keep their own
handlers and delegate the rest to per-domain sub-registrars, so they remain
real entry points rather than re-export shims.

The IPC surface is proved intact rather than assumed: comparing (method,
channel) multisets between HEAD and the split gives 52 registrations across 52
distinct channels on both sides.

Provider-neutrality is preserved -- GitLab and GitHub keep separate, parallel
module layouts rather than being merged behind a shared abstraction.

Verified: oxlint clean, ratchet passes, typecheck clean, full unit suite green
(the one remaining failure is a pre-existing load flake in an untouched file,
green when re-run serially), no new runtime import cycles among 744 modules,
and no lint suppression added anywhere.

src/main/github/project-view/internals.ts

@@ -9,7 +9,7 @@ import {
   noteRepositoryRateLimitSpend,
   type RateLimitBucketKind
 } from '../rate-limit'
-import type { GitHubProjectViewError } from '../../../shared/github/project-types'
+import type { GitHubProjectViewError } from '../../../shared/github/project-result-types'
 import { githubProjectHost } from '../../../shared/github/project-identity'
 import { isDefaultGitHubHost } from '../../../shared/github/repository-identity-key'
 import { isGitHubHostAuthenticatedForGlobalCli } from '../github-enterprise-repository'

src/main/github/project-view/mutations.ts

@@ -21,27 +21,29 @@ import { githubProjectHost } from '../../../shared/github/project-identity'
 import type { PRComment } from '../../../shared/github/comment-types'
 import type { GitHubAssignableUser } from '../../../shared/github/pull-request-types'
 import type { GitHubWorkItemDetails } from '../../../shared/github/work-item-types'
+import type { GitHubProjectFieldMutationValue } from '../../../shared/github/project-types'
+import type {
+  GitHubProjectCommentMutationResult,
+  GitHubProjectMutationResult,
+  ListAssignableUsersBySlugResult,
+  ListIssueTypesBySlugResult,
+  ListLabelsBySlugResult,
+  ProjectWorkItemDetailsBySlugResult
+} from '../../../shared/github/project-result-types'
 import type {
   AddIssueCommentBySlugArgs,
   ClearProjectItemFieldArgs,
   DeleteIssueCommentBySlugArgs,
-  GitHubProjectCommentMutationResult,
-  GitHubProjectFieldMutationValue,
-  GitHubProjectMutationResult,
   ListAssignableUsersBySlugArgs,
-  ListAssignableUsersBySlugResult,
   ListIssueTypesBySlugArgs,
-  ListIssueTypesBySlugResult,
   ListLabelsBySlugArgs,
-  ListLabelsBySlugResult,
   ProjectWorkItemDetailsBySlugArgs,
-  ProjectWorkItemDetailsBySlugResult,
   UpdateIssueBySlugArgs,
   UpdateIssueCommentBySlugArgs,
   UpdateIssueTypeBySlugArgs,
   UpdatePullRequestBySlugArgs,
   UpdateProjectItemFieldArgs
-} from '../../../shared/github/project-types'
+} from '../../../shared/github/project-request-types'
 
 function githubHostExecOptions(args: { host?: string }): { host: string } {
   return { host: githubProjectHost(args.host) }

src/main/github/project-view/project-error-classification.ts

@@ -1,7 +1,7 @@
 // Why: turns raw gh stderr/stdout into the typed GitHubProjectViewError the
 // renderer can act on (auth vs scope vs rate limit vs drift), shared by the
 // project-view read and mutation paths.
-import type { GitHubProjectViewError } from '../../../shared/github/project-types'
+import type { GitHubProjectViewError } from '../../../shared/github/project-result-types'
 import { githubProjectHost } from '../../../shared/github/project-identity'
 
 export type GhGraphqlErrorShape = {