docs: update scheduled function and C# client docs

[clockwork-labs-bot]

Summary

• Document that already-expired schedule rows are not guaranteed to dispatch in scheduled_at order.
• Document the C# client builder WithCompression(Compression) option and the default Brotli compression behavior.
• Document that spacetime list, spacetime rename, and spacetime mcp can resolve a project server from spacetime.json, and align the CLI/MCP skills with that behavior.

Source changes

• Caused by Scheduled functions: Concurrent execution by not awaiting on current run. #5736, which changed scheduled functions so the scheduler dispatches calls without awaiting the current run.
• Caused by SDK Performance Boost #5840, which added/optimized C# SDK compressed message handling and exposes WithCompression(Compression) with Brotli as the default.
• Caused by Make spacetime list, rename and mcp respect the project's server #5883, which made spacetime list, spacetime rename, and spacetime mcp respect a single unambiguous project server from spacetime.json, while adding --no-config escape hatches.

Validation

• pnpm --dir docs typecheck
• pnpm --dir docs build
• git diff --check -- docs/docs/00200-core-concepts/00600-clients/00600-csharp-reference.md skills/csharp-client/SKILL.md
• git diff --check -- docs/docs/00300-resources/00200-reference/00100-cli-reference/00300-spacetime-json.md docs/docs/00300-resources/00200-reference/00150-mcp.md skills/cli/SKILL.md skills/mcp/SKILL.md
• node docs/scripts/sync-agent-skills.mjs

Audit notes

• 2026-09-11 run updated existing open bot/docs-audit PR docs: update scheduled function and C# client docs #5917 and merged current origin/master before adding fixes.
• 2026-09-12 run updated existing open bot/docs-audit PR docs: update scheduled function and C# client docs #5917 and merged current origin/master before adding fixes.
• Commit-impact baseline for the 2026-09-12 run: previous audit branch head 8095803fa / previous master baseline bf15c8109.
• Recent master commits checked first for the 2026-09-12 run: Make spacetime list, rename and mcp respect the project's server #5883 and CI - Re-enable unity jobs #5918.
• CI - Re-enable unity jobs #5918 was CI-only and did not require docs changes.
• Generated public agent skill snapshots were checked with node docs/scripts/sync-agent-skills.mjs.

Rollback safety impact

n/a