Require one source control connection per environment

[daniel-lxs]

Problem

Environments already enforce that all repositories belong to the same GitHub App installation, but there was no analogous rule for the other providers. Task launch resolves a single provider token and base URL per run, so an environment mixing providers — or mixing self-managed instances of the same provider (e.g. two Gitea hosts) — could never authenticate against all of its repositories. Today a single instance per provider makes the host rule vacuous, but it becomes load-bearing groundwork once multiple connections per provider are supported.

Change

• Replace getEnvironmentRepositoryInstallationError with getEnvironmentRepositoryConnectionError in @roomote/types, checking in order:
  1. all repositories share one source control provider,
  2. one GitHub App installation (unchanged behavior),
  3. one instance host (repositories.host).
• Provider and host comparisons ignore null/undefined values, matching the existing installation check, so historical rows that predate the host backfill keep validating.
• All existing enforcement sites now select sourceControlProvider + host and run the broader check: web environment create/update/validate commands and repository selection, MCP createEnvironment/updateEnvironment handlers, environment-definition task launch (requireSingleInstallation option renamed to requireSingleConnection), and declarative environments.

Testing

• New unit suite packages/types/src/__tests__/environment-repository-connection.test.ts covering provider/installation/host mismatches, null-host backfill tolerance, and check precedence.
• New wiring tests in apps/web/.../environments/index.test.ts (multi-host create rejection, mixed-provider validateConfigCommand error).
• pnpm check-types, pnpm lint, pnpm knip all pass; targeted vitest runs for @roomote/types, @roomote/web environments commands, @roomote/api launchTask + environment write auth, and the DB-backed declarative-environments suite all green.

🤖 Generated with Claude Code

[roomote-roomote]

No code issues found. See task

_{Reviewed b962580}

[roomote-roomote]

I reviewed RooCodeInc/Roomote#840 on GitHub and found no code issues. All CI checks are passing.