chore: remove retired OpenAI-Privacy-Filter model + its provenance trail (served model is screenpipe's own); rewrite NOTICE

NOTICE

@@ -1,48 +1,10 @@
 screenpipe-pii-redactor
-Copyright 2026 Mediar, Inc.
+Copyright 2026 screenpipe (https://screenpi.pe)
 
-This product is a derivative work of the OpenAI Privacy Filter
-(https://github.com/openai/privacy-filter), licensed under the
-Apache License, Version 2.0. The full upstream Apache 2.0 license
-text is preserved in LICENSE.upstream-apache2.txt.
+screenpipe's own PII token-classification model, trained in-house for
+redacting PII in screen telemetry (accessibility trees, OCR'd screen
+text, computer-use traces).
 
-The base model architecture, tokenizer, and pretrained weights are the
-work of OpenAI and are licensed Apache 2.0. screenpipe-pii-redactor
-extends those weights via supervised fine-tuning on a custom corpus and
-re-initializes the output head for a 12-label PII taxonomy specific to
-desktop activity logs.
-
-Significant modifications introduced by this derivative:
-  - Output head re-initialized for a 12-class PII label space
-    (29 rows copied from upstream where labels aligned, 20 rows
-    initialized from random for new classes; see model/finetune_summary.json).
-  - Fine-tuned for 3 epochs on a mixed corpus of:
-      * synthetic accessibility / window-title / OCR data
-        (private — not redistributed)
-      * a 25% slice of ai4privacy/pii-masking-300k (CC-BY-4.0)
-        with labels mapped to the 12-class taxonomy
-      * targeted secret-shape augmentation (private)
-  - Context window n_ctx raised from 128 to 256.
-  - Hyperparameters: batch_size=4, lr=1e-4, weight_decay=0,
-    max_grad_norm=1.0, shuffle_seed=1337.
-
-Distribution license:
-
-  - The fine-tuned weights and accompanying materials in this repository
-    (the "Derivative Work") are licensed under CC BY-NC 4.0; see LICENSE.
-  - The Apache 2.0 obligations on the base model are preserved by:
-    (a) shipping LICENSE.upstream-apache2.txt with this repo,
-    (b) attributing OpenAI Privacy Filter in README.md,
-    (c) declaring significant modifications above.
-  - "OpenAI" and "Privacy Filter" are trademarks / brands of OpenAI; this
-    derivative does not use those marks to endorse or suggest endorsement
-    of this work by OpenAI.
-
-Third-party datasets used during fine-tuning:
-
-  - ai4privacy/pii-masking-300k
-    https://huggingface.co/datasets/ai4privacy/pii-masking-300k
-    Licensed CC-BY-4.0.
-
-Questions about license compatibility or commercial use:
-  louis@screenpi.pe
+Distributed under CC BY-NC 4.0 (non-commercial) — see LICENSE.
+For commercial licensing (production deployment, SaaS / API embedding,
+redistribution, custom fine-tunes): louis@screenpi.pe.