docs: add setup guides for Continue, Zed, and Open WebUI MCP clients (#71)

[245678000000]

Summary

Closes #71.

Adds clear, copy-pasteable setup guides and documentation for previously undocumented MCP clients:

• Continue (VS Code & JetBrains IDEs)
• Zed (using native context_servers)
• Open WebUI (via Admin Tools Connections)

Changes

1. New dedicated setup guides:

   • docs/continue-setup.md: Complete setup instructions for Streamable HTTP (https://mcp.opencaselaw.ch/mcp) and SSE (https://mcp.opencaselaw.ch/sse), config file paths across macOS/Linux/Windows, tool verification list, and example queries.
   • docs/zed-setup.md: Direct context_servers JSON block and mcp-remote wrapper options with config paths.
   • docs/open-webui-setup.md: Step-by-step UI configuration in Open WebUI admin panel.

2. Web portal integration (docs/mcp/index.html):

   • Added setup blocks with direct copy-paste configuration snippets for Continue, Zed, and Open WebUI.
   • Added localized setup strings for all 5 supported languages (de, fr, it, rm, en).

3. Cross-references (docs/claude-desktop-setup.md):

   • Added subsections linking to the new client guides under the remote server section.

Verification

• Live MCP endpoint validation: Tested JSON-RPC initialize, tools/list (41 tools discovered), and real query execution (search_decisions for "Mietrecht Kündigung") over Streamable HTTP.
• Repository checks: make smoke and make verify-offline all passed cleanly.

[jonashertner]

Thank you — this closes a real gap (#71 has sat unclaimed for two weeks), the structure matches the house docs style, and the Zed guide is verified correct: I checked context_servers with a bare url against Zed's current MCP docs and it's exactly right, including the mcp-remote fallback. That guide can ship as-is.

Requesting changes on four points, each verified against primary sources rather than taste:

1. Continue: the primary config block is Claude Desktop's format, not Continue's.
Continue's docs specify ~/.continue/config.yaml with a list:

mcpServers:
  - name: swiss-caselaw
    type: streamable-http
    url: https://mcp.opencaselaw.ch/mcp

A top-level "mcpServers" object in config.json (your "Standard Configuration") isn't a documented Continue shape — users pasting it get silent nothing. Your experimental.modelContextProtocolServers fallback is the correct legacy-JSON form and can stay as the alternative. Worth adding: Continue also accepts Claude-style JSON blocks dropped into the .continue/mcpServers/ directory — that's where your JSON snippet belongs if kept. Please make YAML primary here and in the docs/mcp/index.html strings (all five locales).

2. Open WebUI: I can't find "Admin Panel → Settings → Tools → Valve / MCP Connections" in any Open WebUI documentation.
Their docs still route MCP through the mcpo proxy (MCP-to-OpenAPI); "Valves" are function parameters, not a connections menu. If you tested this path against a specific Open WebUI version that has native MCP connections, please say which version and quote the actual menu labels — otherwise this guide should document the mcpo route (uvx mcpo --port 8000 -- npx mcp-remote https://mcp.opencaselaw.ch/mcp, then add http://localhost:8000 as an OpenAPI tool server), with native support mentioned only if version-pinned. A guide with an invented menu path is worse than no guide — the user concludes our server is broken.

3. Both tool-call examples use parameters that don't exist.

• get_law({"law": "BV", …}) → the parameter is abbreviation (or sr_number): get_law({"abbreviation": "BV", "article": "8", "language": "de"})
• find_leading_cases({"statute": "OR 41"}) → the schema is law_code + article: find_leading_cases({"law_code": "OR", "article": "41"})

These are copy-paste examples; they must execute.

4. "41 tools" — the live count is 42.
tools/list against https://mcp.opencaselaw.ch/mcp returns 42 public tools (verified this weekend; docs/canonical_numbers.md was corrected accordingly). Your PR body's "41 tools discovered" suggests the number was taken from the existing page copy rather than a live listing — the page's own pre-existing "41" strings are stale too (that's on us, not you; tracked separately). In the new guides, either say 42 or sidestep the churn with "40+ specialized tools".

Small, non-blocking: the sample output block predates the current response format (totals now render as lower bounds, e.g. Found 1082+ decisions (lower bound; …)) — feel free to paste a fresh response.

If you'd rather not iterate, say so and I'll apply these edits on merge — the contribution is wanted either way.