Release v0.14.0

Summary

Hardens the built-in MCP server against denial-of-service from a single large
or malicious PDF (issue #115), and bumps the bundled oxidize-pdf core from
=3.0.1 to =3.0.4. The core bump makes PdfDocument Send, which lets the
bridge release the GIL during heavy PDF work — so a multi-client MCP deployment
now runs concurrent operations in parallel instead of serializing on one core.

Also documents first-class use from GitHub Copilot and the OpenAI Agents
SDK.

No breaking change to the existing Python API. All new limits are configurable
and ship with generous defaults.

Added — MCP resource caps (issue #115)

Configurable limits, enforced before any heavy work, returning an error with
code RESOURCE_LIMIT:

• OXIDIZE_MAX_PAGES (default 10000) — documents with more pages are rejected
  before extraction begins.
• OXIDIZE_MAX_OUTPUT_BYTES (default 10 MB) — caps the serialized size of a
  tool's JSON response.
• OXIDIZE_MAX_SESSION_BYTES (default 10 MB) — bounds the content a single
  stateful PDF-creation session may accumulate.

The page-count gate and output cap apply to extract_text, read_pdf,
extract_entities, and convert_pdf. get_session_store now honours
OXIDIZE_MAX_SESSIONS (previously a hardcoded 100).

Added — GIL release for concurrent PDF work (issue #115)

Heavy Rust operations now run inside Python::detach, releasing the GIL so
concurrent MCP calls execute in parallel:

• Standalone path/bytes ops: validate_pdf, compare_pdfs,
  detect_pdf_corruption, PdfAValidator.validate_bytes, split_pdf,
  merge_pdfs.
• PdfReader extract/chunk methods: extract_text, extract_text_from_page,
  extract_text_chunks, metadata, get_page, to_markdown, to_contextual,
  chunk, chunk_page, partition, rag_chunks (and the _with_profile /
  _with_source / _with_source_and_config variants),
  extract_text_with_options, extract_fragments_with_options,
  extract_fragments_from_page, extract_plain_text,
  extract_plain_text_lines, get_page_content_streams.

rag_chunks_with_pipeline is intentionally left GIL-held (it runs a
user-supplied analysis pipeline that may re-enter Python).

Added — Copilot & OpenAI Agents SDK integration

• README: .vscode/mcp.json configuration for GitHub Copilot agent mode and an
  OpenAI Agents SDK (MCPServerStdio) snippet.
• examples/openai_agents_quickstart.py — runnable example that connects to the
  oxidize-mcp server over stdio and exposes the 12 tools to an agent.

Changed — upstream bump to oxidize-pdf 3.0.4

Picks up the core change that makes PdfDocument Send
(Rc<ResourceManager> → Arc, RefCell → Mutex), required to release the
GIL in the reader methods.

Security

Mitigates MCP DoS (premortem scenario): a crafted PDF (huge page tree,
unbounded extraction output, or session-content flood) is now rejected at the
gate or bounded, and GIL release prevents one heavy request from freezing all
concurrent sessions.