docs: clarify loader CLI staging guidance

[Teagan42]

What

• expand mcp_plex/loader/AGENTS.md with concrete notes about the staged loader modules and sentinel definitions
• document exactly how the CLI should construct each stage and the orchestrator when wiring the new pipeline

Why

• agents attempting the CLI refactor were missing a single source of truth for which arguments belong on each stage and how to pass them through from CLI options

Affects

• loader package documentation for future refactors

Testing

• not run (documentation-only change)

Documentation

• updated mcp_plex/loader/AGENTS.md

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https://chatgpt.com/codex/tasks/task_e_68e2990a258883289121daca386c107a

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mcp_plex/loader
__init__.py	755	129	83%	182–189, 238, 324–329, 931–932, 976, 978, 1043–1044, 1055–1057, 1060, 1063–1064, 1066, 1088, 1098, 1109–1141, 1156, 1158, 1165–1179, 1182–1196, 1202, 1217–1248, 1253–1286, 1289–1293, 1298–1306, 1316, 1407–1409, 1470–1472, 1830
mcp_plex/loader/pipeline
channels.py	73	2	97%	19–20
enrichment.py	334	44	87%	78, 80, 87, 91, 134–137, 170, 191, 211, 219–221, 228–231, 234–236, 244, 301, 357, 380, 384, 386, 412, 430, 465, 471, 474–482, 508, 532, 603, 606–608
ingestion.py	81	8	90%	67, 98–108, 129, 157, 179
orchestrator.py	85	5	94%	48, 112, 141, 164–165
persistence.py	117	9	92%	109, 151–152, 162, 167, 171–173, 201
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	2321	237	90%

Tests	Skipped	Failures	Errors	Time
128	0 💤	0 ❌	0 🔥	46.626s ⏱️