Add installation-scoped bulk pause/dry-run endpoint (currently strictly per-repo)

[JSONbored]

Problem

A hosted tenant with multiple repos under one installation has no way to pause/dry-run all of them at once — only strictly per-repo agentPaused/agentDryRun (edited one repo at a time via MaintainerSettings, /v1/repos/:owner/:repo/settings) exists today. Decided: add a bulk control, distinct from the separate global operator kill-switch (getGlobalAgentFrozenState), which stays a deliberately separate singleton.

Area

src/api/routes.ts, src/services/control-panel-roles.ts.

Proposal

Add an installation-scoped bulk pause/dry-run endpoint layered on top of the existing per-repo settings — applies the same per-repo flags across every repo in the tenant's installation in one call, with its own audit-trail entry distinct from the global kill-switch's.

Deliverables

• A bulk endpoint applying pause/dry-run across all of a tenant's repos.
• Audit-trail entry distinguishing this from both per-repo edits and the global kill-switch.

Resources

• Existing per-repo settings pattern (/v1/repos/:owner/:repo/settings)
• The global kill-switch (getGlobalAgentFrozenState) — stays separate, not touched by this

Boundaries

Installation-scoped bulk control only — does not touch or replace the global operator kill-switch.

maintainer-only — blast-radius-relevant control surface, needs maintainer review.

[linear-code]

JSO-5422