Business rationale

Issue #416 reports a real mismatch between the documentation and the product surface: users were led to believe arbitrary command-based stdio MCP providers could be configured through the remote-provider UI, even though Osaurus remote MCP providers are URL-based HTTP/SSE endpoints and the supported local stdio bridge is osaurus mcp. This repair keeps the branch scoped to documentation so reviewers can validate the user-facing guidance without re-reviewing old Swift/UI churn; the observable improvement is that the docs now distinguish first-party osaurus mcp stdio from unsupported third-party command/args launchers.

Coding rationale

The previous draft mixed docs, endpoint validation, UI text, and stale Swift changes from an old base. I repaired the branch by recording current origin/main ancestry with a normal merge, restoring code/workflow/package files to current main, and reapplying only the docs changes allowed by lane T-E. I deliberately did not add the unrelated Swift formatting changes needed to satisfy the local full gate, because that would violate the docs-only trust boundary for this PR and make the maintainer review a mixed code/docs change.

Acceptance criteria

• osaurus mcp is documented as the supported stdio bridge.
• Remote MCP Providers docs state URL-based HTTP/SSE only.
• Third-party command/args, env, and working-directory stdio launchers are explicitly out of scope for remote providers.
• PR diff against current origin/main is docs-only.
• Full local gate is green on the PR head. Blocked by current-main swift-format failures that would require unrelated Swift edits in this docs-only lane.

Quality gate

• git diff --check origin/main..HEAD -- docs/DEVELOPER_TOOLS.md docs/FEATURES.md docs/REMOTE_MCP_PROVIDERS.md — clean
• git diff --exit-code origin/main..HEAD -- Packages App .github .gitignore osaurus.xcworkspace — clean, proving no code/workflow/package diff remains
• Markdown wording/link sanity via rg — clean
• swift-format / swiftlint / shellcheck — blocked locally by unrelated current-main Swift formatting failures
• swift test --package-path Packages/OsaurusCLI --parallel — not rerun for this draft repair
• make ci-test — not rerun for this draft repair
• swift build --package-path Packages/OsaurusCore -c release — not rerun for this draft repair
• Archive freshness — confirmed: git fetch --all --prune completed at 2026-05-17T13:00:49Z before push

Debug evidence

The repair changed the PR surface from mixed code/docs to docs-only. Before repair, PR #1058 listed Swift files such as Packages/OsaurusCore/Managers/MCPProviderManager.swift, Packages/OsaurusCore/Views/Settings/ProvidersView.swift, and Packages/OsaurusCore/Tests/MCP/MCPProviderEndpointValidationTests.swift; after repair, git diff --name-status origin/main..HEAD lists only docs/DEVELOPER_TOOLS.md, docs/FEATURES.md, and docs/REMOTE_MCP_PROVIDERS.md. The pushed head is 73e337c2b672b1b965c425d2ce4e2036b50131a2.

Rollback

Revert this PR branch to the prior draft head 7d1f3c111191262c64d42b7972c5135461524b43, or close this draft and keep the current docs from origin/main.