GitHub App rename

[JSONbored]

Problem: The GitHub App's display name and public install URL still carry the old brand.

Area: Infra / GitHub App

Proposal: Rename the App's display name in GitHub settings (its public slug derives automatically from the name). This has been researched and confirmed safe: existing installations and webhook deliveries are keyed by the App's immutable ID, not its slug, so no self-host installation needs to be reinstalled or reconfigured. GitHub does not automatically redirect old App install URLs, so every hard-coded install link in documentation needs a follow-up sweep to the new URL.

Deliverables:

• App renamed.
• Every documented install link updated to the new URL.

Acceptance criteria:

• An already-installed test repository continues receiving webhook deliveries with zero reconfiguration on its end.
• Every documented install link resolves to the new, correct URL.

Test scenarios:

• Trigger a webhook-generating event on a repo that already has the App installed, immediately after the rename, and confirm delivery.
• Click through every documented install link post-rename.

Resources:

• The App slug configuration value and the README's install link.

Boundaries:

• This is an in-place rename, not a new App registration — do not create a second App entity.

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Part of #4761.

[linear-code]

JSO-3444

[JSONbored]

Addendum — one more code call site for the install-link sweep: src/services/subnet-interface.ts defines PUBLIC_GITHUB_APP_SLUG = "gittensory-orb" and uses it to build both interfaces.githubApp.slug and interfaces.githubApp.installUrl (https://github.com/apps/${PUBLIC_GITHUB_APP_SLUG}) in the public, machine-readable subnet-interface descriptor — a JSON payload other tooling can parse, not just prose. The same file also hardcodes provider.name: "Gittensory" as data. Worth calling out explicitly since "sweep documented install links" could read as docs-prose-only; this is a source constant that needs updating in the same commit as the App's actual rename, or the machine-readable descriptor will keep advertising the old slug/name after the App itself has been renamed.