feat: integrate persistence stage upsert orchestration

[Teagan42]

Summary

• wire the loader pipeline to the persistence stage so the stage manages batching, queue emission, and concurrent upsert workers
• expand the persistence stage to chunk point batches, run Qdrant writes with retry callbacks, and notify the pipeline for progress accounting
• add unit tests covering successful upserts, retry queue population, semaphore release on errors, and bump the project version to 0.26.69

Testing

• uv run ruff check .
• uv run pytest

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https://chatgpt.com/codex/tasks/task_e_68e2d3eef50c83289cafe78ad1d1452e

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mcp_plex/loader
__init__.py	746	129	83%	173–180, 229, 315–320, 922–923, 967, 969, 1034–1035, 1046–1048, 1051, 1054–1055, 1057, 1079, 1089, 1100–1132, 1147, 1149, 1156–1170, 1173–1187, 1193, 1208–1239, 1244–1277, 1280–1284, 1289–1297, 1307, 1375–1377, 1438–1440, 1798
mcp_plex/loader/pipeline
channels.py	70	2	97%	19–20
enrichment.py	334	44	87%	77, 79, 86, 90, 133–136, 169, 190, 210, 218–220, 227–230, 233–235, 243, 300, 356, 379, 383, 385, 411, 429, 464, 470, 473–481, 507, 531, 602, 605–607
ingestion.py	81	8	90%	67, 98–108, 129, 157, 179
persistence.py	73	6	92%	103, 111, 116, 120–122
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	2180	229	89%

Tests	Skipped	Failures	Errors	Time
123	0 💤	0 ❌	0 🔥	57.045s ⏱️