docs: outline loader multi-worker architecture plan

[Teagan42]

What

• add a loader multi-worker re-architecture plan describing the ingestion, enrichment, and upsert stages

Why

• capture a detailed approach for parallelizing the loader before implementing the changes

Affects

• documentation under docs/plans

Testing

• not run (documentation-only change)

Documentation

• new plan document added

---

https://chatgpt.com/codex/tasks/task_e_68e24dc3635483288aa92a4c0a632ea3

[Copilot]

Pull Request Overview

This PR adds a comprehensive documentation plan for re-architecting the loader system to support multi-worker parallelization. The document outlines a detailed approach for separating the ingestion, enrichment, and upsert stages into concurrent workers.

Key changes:

• Architectural plan for pipeline decoupling using asyncio queues
• Configuration changes for tunable chunk sizes and worker counts
• Implementation roadmap with specific refactoring steps

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mcp_plex/loader
__init__.py	628	24	96%	201, 256, 258–260, 276, 362–367, 944–949, 1072–1074, 1085–1087, 1099–1101, 1374
mcp_plex/server
__init__.py	614	29	95%	43–44, 119–120, 148, 252, 256, 277–280, 297, 362, 365, 402, 420–421, 458, 1109, 1131–1137, 1173, 1191, 1196, 1214, 1338, 1375
__main__.py	4	4	0%	3–8
config.py	48	7	85%	50, 52–55, 65, 76
TOTAL	1496	64	96%

Tests	Skipped	Failures	Errors	Time
100	0 💤	0 ❌	0 🔥	59.180s ⏱️