feat: raw accept - incoming/ als abgeleiteter Rohablage-Eingang (schliesst #58)

Files changed:
- .gitignore
- CHANGES.md
- README.md
- VERSION
- docs/pipeline-rationale.md
- instructions/bootstrap.md
- instructions/wiki-ingest/SKILL.md
- raw/CONTRACT.md
- tools/CONTRACT.md
- tools/chemenu/cli.py
- tools/chemenu/commands/dist_cmd.py
- tools/chemenu/commands/docs_verify.py
- tools/chemenu/commands/raw_cmd.py
- tools/chemenu/tests/test_dist_cmd.py
- tools/chemenu/tests/test_docs_verify.py
- tools/chemenu/tests/test_raw_cmd.py

raw/CONTRACT.md

@@ -20,6 +20,52 @@ from `kb/` is what makes that boundary visible.
 | `notes/` | Personal notes, meeting notes, conversation transcripts |
 | `assets/` | Images, diagrams, configuration files, and other binaries |
 
+This table is read by `tools/wikitool docs verify` against `dist_cmd.RAW_SUBDIRS`, the single
+place the four names are declared in code - the two are kept in sync mechanically rather than by
+convention (Gitea #58).
+
+## Getting a file in: `incoming/`
+
+`raw/` is never chosen by hand. A file to be ingested is dropped into the gitignored top-level
+`incoming/`, under the subdirectory naming its type - `incoming/articles/`, `incoming/documents/`,
+`incoming/notes/`, `incoming/assets/`, mirroring the table above. That placement is the only
+classification a human makes: **what kind of document this is**, not where it ends up on disk.
+Everything past it - the target directory, whether a bundle directory is needed, its name, the
+move itself - is computed by `tools/wikitool raw accept`.
+
+```bash
+tools/wikitool raw accept incoming/documents/handbuch.pdf
+# -> raw/documents/handbuch.pdf
+```
+
+**A bundle directory is created only from the second file onward.** One file promoted alone needs
+no directory of its own and lands as `raw/<type>/<name>`; promoting several files of one source in
+the same call nests them under `raw/<type>/<stem>/`, named after the first file's stem:
+
+```bash
+tools/wikitool raw accept incoming/documents/handbuch.pdf incoming/documents/handbuch.md
+# -> raw/documents/handbuch/handbuch.pdf
+# -> raw/documents/handbuch/handbuch.md
+```
+
+This is why the 29 files already in `raw/` sit directly under their type directory rather than
+each in its own bundle: an eindateiige Quelle is already in the form the rule produces, not an
+exception to it - nothing was reorganised to reach this state.
+
+A bundle's type directory is the **source's** type, not any one file's - a diagram that belongs to
+a `documents/` source is promoted from `incoming/documents/`, not `incoming/assets/`; `assets/` is
+for a source that is itself an asset.
+
+`tools/wikitool raw accept --page "Source - X" ...` additionally extends an existing source page's
+`raw_files:` in the same call. If that raises the page past one file, its already-promoted file is
+folded into the new bundle alongside the one(s) just accepted - the file that started single does
+not stay single once a second one belongs beside it.
+
+`incoming/` is read by an ingest session, never by `sources coverage` or `lint`: both walk `raw/`
+only, so a file waiting there is not yet a finding. It is also never committed - proven, not
+merely asserted, by `docs verify`'s ignore-rule canaries - which is what makes accepting a file the
+moment its immutability under the rules below begins, not the moment it was dropped.
+
 ## Rules
 
 - **Immutable.** Never edit, reformat, summarize, or "clean up" a file after it lands here.