docs: add Russian project report notebook (notebooks/report.ipynb)

Runnable end-to-end report combining narrative, code, and inline figures:
data and .chord format, transformer working principle, two-stage training
curves, perplexity (3.58 -> 2.15), distribution-shift plot with a reading
legend, qualitative examples, and a generation demo. Written in a
first-person student voice.

- CLAUDE.md: report is now a Jupyter notebook; GOST formatting dropped
- requirements.txt: add nbconvert + ipykernel (optional, for the notebook)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CLAUDE.md

@@ -131,7 +131,7 @@ No formal blind listening test (out of scope for the deadline).
 ## Working language
 
 - **Code, identifiers, code comments, log messages, commit messages: English.**
-- **User-facing output, the academic report, and the README user guide: Russian** (per university requirements; the report must comply with GOST).
+- **User-facing output, the academic report, and the README user guide: Russian** (per university requirements). The report is delivered as a runnable Jupyter notebook (`notebooks/report.ipynb`), **not** a GOST-formatted document — strict GOST formatting was explicitly dropped by the author (this is a student project, not formal coursework).
 - **Conversations with the developer (the author): Russian.**
 
 When generating commit messages or code comments, write in English. When generating the report or any user-facing text, write in Russian.

requirements.txt

@@ -15,5 +15,9 @@ matplotlib==3.10.9
 # Web UI (optional — only needed for app.py)
 gradio==6.16.0
 
+# Report notebook (optional — only needed to run notebooks/report.ipynb)
+nbconvert==7.17.1
+ipykernel==7.2.0
+
 # Testing
 pytest==9.0.3