#16251: docs: remove note about personal single-user access from trusted proxy auth guidance

## Summary A small follow up PR related to #1710. Describe the problem and fix in 2–5 bullets: Updates the trusted proxy auth docs "when not to use" section and removes the bullet point about them not being suitable for personal use. I use an identity aware proxy for my homelab to harden access to OpenClaw as well as provide hardened access via SSH. That was the whole reason I implemented #15940. 😅 ## Change Type (select all) - [ ] Bug fix - [ ] Feature - [ ] Refactor - [x] Docs - [ ] Security hardening - [ ] Chore/infra ## Scope (select all touched areas) - [x] Gateway / orchestration - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [ ] Integrations - [ ] API / contracts - [ ] UI / DX - [ ] CI/CD / infra ## Linked Issue/PR - Related #1710 ## User-visible / Behavior Changes List user-visible changes (including defaults/config). If none, write `None`. ## Security Impact (required) - New permissions/capabilities? (`Yes/No`) - Secrets/tokens handling changed? (`Yes/No`) - New/changed network calls? (`Yes/No`) - Command/tool execution surface changed? (`Yes/No`) - Data access scope changed? (`Yes/No`) - If any `Yes`, explain risk + mitigation: ## Repro + Verification ### Environment - OS: - Runtime/container: - Model/provider: - Integration/channel (if any): - Relevant config (redacted): ### Steps N/A ### Expected - ### Actual - ## Evidence N/A ## Human Verification (required) What you personally verified (not just CI), and how: N/A ## Compatibility / Migration N/A ## Failure Recovery (if this breaks) N/A ## Risks and Mitigations N/A <!-- greptile_comment --> <h3>Greptile Summary</h3> Removes outdated guidance from the trusted-proxy auth documentation. The removed bullet point incorrectly suggested that trusted-proxy auth wasn't suitable for personal single-user access, but as the PR author demonstrates, identity-aware proxies work well for hardening homelab deployments. The documentation still appropriately references Tailscale as a simpler alternative for tailnet-only access in the "Related" section. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with no risk - Documentation-only change that removes a single bullet point from the "When NOT to Use" section. The removed guidance was outdated and contradicted the author's successful real-world use case. No code changes, no behavioral changes, and the remaining documentation is coherent and complete. - No files require special attention _{Last reviewed commit: c50b814} <!-- greptile_other_comments_section --> _{(4/5) You can add custom instructions or style guidelines for the agent [here](https://app.greptile.com/review/github)!} <!-- /greptile_comment -->