Read the user's own lesson notes, and the class register behind them

Schulcloud says what was uploaded and WebUntis says what was scheduled.
Neither says what was *taught* — which point the teacher laboured, which
example landed, what "will definitely come up". That lives in two places
this server could not reach: the notes the user takes in the lesson, and
WebUntis' class register.

Notes are a directory of Markdown files (NOTES_DIR), not a table. They
have to be writable from a phone in a classroom, readable when Postgres
is down, and outlive this project, and files are the only shape that is
all three — so the files are the truth and the index is a view of them,
the same split as file_texts and the mirror. list_notes and get_note read
disk, so they answer before the first crawl; search, what_changed and all
three German prompts read them alongside the Schulcloud material.

add_note writes one, and is the only thing in this server that writes
anything. That is not a hole in the read-only invariant but a different
store: it is bounded to NOTES_DIR by the same safeComponent/resolveWithin
pair that stops a hostile Schulcloud filename escaping the mirror, so a
note titled ../../.ssh/authorized_keys becomes a filename. Schulcloud and
WebUntis stay GET-only and allowlisted respectively. NOTES_READONLY
refuses writes outright.

Appending targets the *lesson*, not the title: "halt das auch noch fest"
mid-lesson carries a new title, and deriving the path from it would start
a second note every time, which is the one thing append exists to prevent.

Notes.app has no export — its bodies are compressed protobuf and the
iCloud copy is encrypted — so scripting the app is not the clumsy route
to the notes but the only one. scripts/export-apple-notes.js reads them
through AppleScript into one JSON object per line, and `schulcloud note
import` converts the HTML to Markdown, takes the Notes folder as the
subject and the *creation* date as the lesson's date. Attachments cannot
come across; a note that was a photo of the board imports as a line
saying so, because importing it empty would hide the loss.

The class register needed one API property to become cheap:
getLessonTopic2017 answers per *series*, not per period, so a term is
reconstructed by asking about the latest period of each lesson series and
merging back by id — a few dozen calls for a school year rather than one
per lesson. untis_lesson_topics now takes a subject as well as a period
id, and UNTIS_HISTORY_DAYS of register goes into the index under a kind
of its own, so "what did we actually do before the test" is searchable.

Sharing the snapshot rather than duplicating it caught one thing on the
way: the search tool's live path had to learn notes too, or fresh=true
would have quietly disagreed with the index.

305 tests; 88/89 smoke against the local instance, the one failure being
the H5P service that instance does not run. The live smoke could not be
retaken: that session has lapsed and needs a fresh jwt cookie.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -2,8 +2,9 @@
 
 Read-only access to a [Schulcloud](https://github.com/hpi-schul-cloud) account —
 courses, boards, lessons, tasks and files — plus the timetable from
-[WebUntis](https://www.untis.at/), for **Claude**, via MCP, and for **you**, via
-a CLI that mirrors your coursework to disk.
+[WebUntis](https://www.untis.at/) and **the notes you take in class**, for
+**Claude**, via MCP, and for **you**, via a CLI that mirrors your coursework to
+disk.
 
 Both are front ends over one core library and one live Schulcloud session, kept
 alive on a Pi.
@@ -19,8 +20,10 @@ instance, not inferred from the upstream source.
 > *"Summarise the routing lesson from the LF10 course."*
 > *"What do I have tomorrow, and has anything been cancelled?"*
 > *"Quiz me on the DIN 5008 exercise from the DK room."*
+> *"What did we actually cover in Deutsch before the test — and what did I write down?"*
 
-Twenty-eight tools, all read-only:
+Thirty-one tools. Everything that touches Schulcloud and WebUntis is read-only;
+`add_note` writes a file in your own notes directory and nowhere else.
 
 | | |
 |---|---|
@@ -51,6 +54,9 @@ Twenty-eight tools, all read-only:
 | `api_get` | GET-only escape hatch for uncovered API surface |
 | `untis_timetable` | the school day from **WebUntis**: lessons, Entfall, Vertretung, room changes, period notes |
 | `untis_homework` | homework from WebUntis' class register — a separate list from Schulcloud's tasks |
+| `list_notes` | your own lesson notes — what you wrote down, by subject or date |
+| `get_note` | one of your notes in full |
+| `add_note` | write a note down during or after a lesson |
 | `untis_lesson_topics` | what previous lessons of a subject actually covered ("Unterrichtsinhalt") |
 
 `download_file` extracts text from **PDF, DOCX, XLSX, PPTX and OpenDocument**
@@ -63,6 +69,12 @@ MCP resource (`schulcloud://courses/<id>`, `schulcloud://rooms/<id>`) holding
 the same overview `get_course` and `get_room` return. In Claude Code, type `@`
 and part of the course name.
 
+**Your own notes are the third source.** Schulcloud has the material and
+WebUntis has the schedule; neither has what the teacher actually stressed. Point
+`NOTES_DIR` at a directory of Markdown files and `search`, `what_changed` and
+all three prompts read it alongside everything else — including a migration path
+out of Apple Notes. See [docs/NOTES.md](docs/NOTES.md).
+
 **Three ready-made prompts**, in German because the school is:
 
 | | |
@@ -87,6 +99,8 @@ schulcloud sync                # mirror coursework to ~/Schulcloud
 schulcloud refresh --course <id>
 schulcloud fs tree /courses    # browse the file manager ("Dateien")
 schulcloud fs get "/courses/<course>/<folder>"
+schulcloud note ls --subject Deutsch
+pbpaste | schulcloud note add --title Subnetting --subject LF07
 schulcloud token set           # the monthly chore: hand the Pi a fresh Schulcloud token
 ```
 
@@ -186,14 +200,15 @@ bypass, "what's new since…" — are sketched with their trade-offs in
 
 ```
 src/
-  core/         client, types, board assembly, crawler, extraction, paths, WebUntis
+  core/         client, types, board assembly, crawler, extraction, paths,
+                WebUntis and its class register, your own notes
   store/        Postgres: crawl generations, diffs, full-text search
   indexer/      crawl → persist → mirror bytes → extract text → index
   mcp/          MCP server, tools, resources and prompts
   http/         express app, bearer auth, /api for the CLI
   cli/          CLI config, API client, sync engine
   bin/          http, stdio and cli entry points
-docs/           API findings, auth, deployment, CLI, roadmap
+docs/           API findings, auth, deployment, CLI, notes, roadmap
 deploy/         Caddyfile snippet, the Pi's compose file
 scripts/        probe, smoke, session diagnostics
 vendor/         upstream clones, git-ignored, for reference only