feat(mcp): improve remote ingest guidance

Make upload-ticket auth the default remote-agent path by returning complete upload URLs and updating service output/docs.

Add validate_upload and preview_upload_metadata for lightweight file checks and exact sha256 duplicate warnings before ingest.

Expose version, capability schema, file-index freshness, queue state, and known limitations through get_mcp_capabilities.

Validation: python3 -m unittest discover -v; python3 -m compileall obsidian_wiki tests scripts; git diff --check.

README.md

@@ -464,31 +464,33 @@ This adds write-capable MCP tools to the same `wiki-file-assets` server and bear
 
 - `get_ingest_upload_instructions` — returns the preferred upload methods, HTTP endpoint path, fields, limits, and curl example for remote agents.
 - `ingest_text_note` — accepts a short thought/note as text, wraps it as a temporary markdown upload, and optionally starts the normal fixed `/wiki-ingest` job.
-- `create_ingest_upload_ticket` — returns a short-lived, single-use upload token for the HTTP endpoint so remote agents can upload with curl without reading the main MCP bearer token.
+- `create_ingest_upload_ticket` — returns a short-lived, single-use upload token plus the upload URL for remote-agent HTTP uploads.
+- `validate_upload` — checks planned file names, sizes, sha256 values, count limits, and exact duplicate sha matches before upload.
+- `preview_upload_metadata` — previews completed uploads, inferred metadata, and exact duplicate warnings before starting ingest.
 - `check_ingest_opencode_readiness` — verifies the local OpenCode binary, required run flags, project ingest skills, and optionally runs a no-write smoke test that confirms `wiki-ingest` can be loaded.
 - `start_ingest_job` — queues a local `opencode run --auto --format json` job with a fixed `/wiki-ingest` prompt for the completed uploads.
 - `get_ingest_job_status`, `get_ingest_job_result`, `cancel_ingest_job` — inspect or cancel the local job.
 
-The managed service config sets the OpenCode model server-side. By default ingest uses `OBSIDIAN_MCP_INGEST_OPENCODE_MODEL=openai/gpt-5.5` and `OBSIDIAN_MCP_INGEST_OPENCODE_VARIANT=high` for stronger file processing. Change those in `.runtime/obsidian-wiki-mcp.env` on the server if needed; remote MCP clients do not choose the model per call.
+The managed service config sets the OpenCode model server-side. By default ingest uses `OBSIDIAN_MCP_INGEST_OPENCODE_MODEL=openai/gpt-5.5` and `OBSIDIAN_MCP_INGEST_OPENCODE_VARIANT=high` for stronger file processing. It also writes `OBSIDIAN_MCP_PUBLIC_BASE_URL` from the detected remote address so ticket responses can include a complete upload URL; set it manually when the service is behind a tunnel, reverse proxy, or custom DNS name. Change these values in `.runtime/obsidian-wiki-mcp.env` on the server if needed; remote MCP clients do not choose the model per call.
 
 For short text thoughts, notes, findings, or pasted context, call `ingest_text_note(text, title?, project?, doc_type_hint?, note?, start_job?)`. It uses `doc_type_hint="thought"` by default and returns the created upload plus the queued job when `start_job=true`.
 
-For binary files and larger source documents, use the HTTP upload endpoint. If the remote agent cannot read the main MCP bearer token, first call `create_ingest_upload_ticket`, then upload with the returned token:
+For binary files and larger source documents, remote agents should use upload tickets by default: call `create_ingest_upload_ticket(start_job=false)`, upload with the returned `upload_url` and `X-Obsidian-Wiki-Upload-Token`, call `preview_upload_metadata(upload_ids)`, then call `start_ingest_job(upload_ids)` when the preview looks correct:
 
 ```bash
 curl -H "X-Obsidian-Wiki-Upload-Token: <upload-token>" \
   -F "files=@drawing.pdf" \
   -F "project=bjd" \
   -F "doc_type_hint=drawing" \
-  -F "start_job=true" \
-  http://127.0.0.1:8765/mcp-ingest/uploads
+  -F "start_job=false" \
+  <upload_url>
 ```
 
-The endpoint accepts repeated `files` fields plus optional `project`, `doc_type_hint`, `note`, and `start_job` fields. It accepts either the same bearer token as `/mcp` or the single-use upload ticket header. Upload tickets are consumed only by authorized `POST` uploads, not by accidental `GET`/wrong-method requests. The upload route enforces configured `--allowed-host` and `--allowed-origin` checks, and rejects oversized request bodies with HTTP `413` before parsing multipart content. Base64 file upload is intentionally not exposed as an MCP tool because large JSON arguments are fragile in many agent tool-call implementations.
+The endpoint accepts repeated `files` fields plus optional `project`, `doc_type_hint`, `note`, and `start_job` fields. It still accepts the same bearer token as `/mcp` for local/admin compatibility, but remote agents should prefer single-use upload tickets. Upload tickets are consumed only by authorized `POST` uploads, not by accidental `GET`/wrong-method requests. The upload route enforces configured `--allowed-host` and `--allowed-origin` checks, and rejects oversized request bodies with HTTP `413` before parsing multipart content. Base64 file upload is intentionally not exposed as an MCP tool because large JSON arguments are fragile in many agent tool-call implementations. Duplicate detection is exact sha256 matching only; it does not replace human review for near-duplicate or renamed source files.
 
 Run `check_ingest_opencode_readiness` before the first remote upload. Use `run_smoke_test: true` when you want OpenCode itself to prove it can load the project `wiki-ingest` skill; otherwise the static preflight is also run automatically before every `start_ingest_job`.
 
-Uploads and text notes land under `.runtime/mcp-ingest/uploads/`, outside the Obsidian vault, and are treated only as temporary source staging. Job state and logs live under `.runtime/mcp-ingest/jobs/`. Remote upload and job responses expose upload/job ids, hashes, states, and log tails, but omit local runtime file paths; the internal job record still keeps paths so the fixed local OpenCode prompt can ingest only the uploaded files. The MCP server refuses to enable ingest if `OBSIDIAN_MCP_INGEST_RUNTIME_ROOT` points inside the vault; let `wiki-ingest` decide how to archive sources into `_sources/archive/`, update registries, and rebuild the file index. The ingest prompt is generated by the MCP service, requires OpenCode to load `wiki-ingest`, and restricts OpenCode to the uploaded file list; clients cannot pass arbitrary shell commands through this interface. Because enabling ingest gives the remote token write access to the vault through local OpenCode, keep it on a trusted network and rotate the token if it has been shared too broadly.
+Uploads and text notes land under `.runtime/mcp-ingest/uploads/`, outside the Obsidian vault, and are treated only as temporary source staging. Job state and logs live under `.runtime/mcp-ingest/jobs/`. Remote upload and job responses expose upload/job ids, hashes, states, and log tails, but omit local runtime file paths; the internal job record still keeps paths so the fixed local OpenCode prompt can ingest only the uploaded files. `get_mcp_capabilities` includes `server_version`, `capabilities_schema_version`, `tools_version`, file-index freshness, ingest queue state, and known limitations so remote agents can detect stale client instructions. The MCP server refuses to enable ingest if `OBSIDIAN_MCP_INGEST_RUNTIME_ROOT` points inside the vault; let `wiki-ingest` decide how to archive sources into `_sources/archive/`, update registries, and rebuild the file index. The ingest prompt is generated by the MCP service, requires OpenCode to load `wiki-ingest`, and restricts OpenCode to the uploaded file list; clients cannot pass arbitrary shell commands through this interface. Because enabling ingest gives the remote token write access to the vault through local OpenCode, keep it on a trusted network and rotate the token if it has been shared too broadly.
 
 To let a remote MCP client ask synthesized questions against the compiled wiki, enable the `query` tool group: