tools: Export- und Eingangsordner im Backup-Ziel - Überschneidungsregel nur noch auf <ziel>/git und den eigenen Maschinenordner, Laufzeitprüfung auf Vorfahren in upload collect und export run (#216); 10.1.0-beta.16

Files changed:
- CHANGES.md
- VERSION
- docs/how-to/back-up-to-a-synced-folder.md
- docs/how-to/collect-from-a-synced-folder.md
- docs/how-to/export-to-a-synced-folder.md
- docs/reference/commands/exports.md
- docs/reference/commands/raw-material-and-uploads.md
- docs/reference/configuration.md
- tools/CONTRACT.md
- tools/chemenu/backup.py
- tools/chemenu/collect.py
- tools/chemenu/commands/export_cmd.py
- tools/chemenu/commands/upload_cmd.py
- tools/chemenu/config_shapes.py
- tools/chemenu/page_export.py
- tools/chemenu/tests/test_collect.py
- tools/chemenu/tests/test_export_run.py
- tools/chemenu/upload.py

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

docs/reference/configuration.md

@@ -396,7 +396,7 @@ exits 42 for them.
 <!-- wikitool:reference-config-intake -->
 | Field | Tier | Type | Required | Default | Description |
 |-------|------|------|----------|---------|-------------|
-| `channels` | checkout, gate | object | yes | - | Channel name (lower-case letters, digits and hyphens) to channel. The name goes into the manifest of what the channel delivers and is the argument of `upload collect`. Every channel has `handler` (`mcp`, `folder` or `command`), `max_bytes` (the largest single file) and `allowed_extensions` (each starting with `.`, compared case-insensitively). Then per handler: `mcp` takes `identity_header` (the request header the authenticating middleware sets to the submitter's identity, default `X-Forwarded-User`) and, required, `quota_submissions_per_day` and `quota_bytes_per_day` (per submitter, over any rolling 24 hours); `folder` takes `path` (required: an absolute path outside the instance, read without descending into subdirectories) and `settle_seconds` (default 60: a file whose modification or creation time is younger is left alone); `command` takes `command` (required: the name of an entry of `commands`). At most one channel has the handler `mcp`. A field the handler does not take is an error. |
+| `channels` | checkout, gate | object | yes | - | Channel name (lower-case letters, digits and hyphens) to channel. The name goes into the manifest of what the channel delivers and is the argument of `upload collect`. Every channel has `handler` (`mcp`, `folder` or `command`), `max_bytes` (the largest single file) and `allowed_extensions` (each starting with `.`, compared case-insensitively). Then per handler: `mcp` takes `identity_header` (the request header the authenticating middleware sets to the submitter's identity, default `X-Forwarded-User`) and, required, `quota_submissions_per_day` and `quota_bytes_per_day` (per submitter, over any rolling 24 hours); `folder` takes `path` (required: an absolute path outside the instance, read without descending into subdirectories; it must not be or lie in `<backup.target>/git` or `<backup.target>/<machine>`, and `upload collect` refuses a folder that holds or lies in any machine folder, bare repository or export) and `settle_seconds` (default 60: a file whose modification or creation time is younger is left alone); `command` takes `command` (required: the name of an entry of `commands`). At most one channel has the handler `mcp`. A field the handler does not take is an error. |
 | `commands` | checkout, names a command | object | no | `{}` | Command name to command: an array of the program and its arguments, run by the `command` handler without a shell, with stdin closed and a timeout of 300 s, and a staging directory appended as the last argument. Exit 0 turns each regular file at the top level of that directory into a submission; anything else takes nothing over and prints the end of the program's stderr. |
 
 - **Absent:** No channel: the `submit` tool is not registered and `upload collect` has nothing to collect. A valid state; `doctor` reports `OK`.
@@ -604,7 +604,7 @@ host name for one, do reach the synced folder.
 <!-- wikitool:reference-config-backup -->
 | Field | Tier | Type | Required | Default | Description |
 |-------|------|------|----------|---------|-------------|
-| `target` | checkout, gate | string | yes | - | The backup folder: an absolute path outside the instance. `backup init` creates `<target>/git` in it, `backup run` writes only to `<target>/<machine>/`. |
+| `target` | checkout, gate | string | yes | - | The backup folder: an absolute path outside the instance. `backup init` creates `<target>/git` in it, `backup run` writes only to `<target>/<machine>/`. Everything else in the folder is the sync folder's: an `export` target or an `intake` folder may sit beside `git` and the machine folders (`<target>/Export`, `<target>/Inbox`), but none may be, or lie in, one of them. |
 | `machine_data` | checkout, gate | boolean | no | `false` | Mirror this machine's files after every `publish` that pushed, and with `backup run`: `.wikitool-local.json`, `ENVIRONMENT.md`, what waits in `incoming/`, and `extra`. |
 | `machine_name` | checkout | string | no | the host name | The name of this machine's folder under the target. Every character outside letters, digits, `-` and `_` becomes `-`, and leading and trailing `-` are dropped; a name that is empty afterwards, or `git` in any case, is an error. |
 | `extra` | checkout, gate | array of strings | no | `[]` | Further files or directories to mirror, relative to the instance. One that resolves outside the instance, or into `.git/`, is an error. |
@@ -644,7 +644,7 @@ them into a staging directory and hands that to a converter of this checkout.
 <!-- wikitool:reference-config-export -->
 | Field | Tier | Type | Required | Default | Description |
 |-------|------|------|----------|---------|-------------|
-| `targets` | checkout, gate | object | yes | - | Target name (lower-case letters, digits and hyphens) to target; the name is the argument of `export run`. Every target has `handler` (`markdown`: the pages as Markdown files; `command`: the same Markdown run through a converter of this checkout), `path` (an absolute path outside the instance; it must not lie in or contain another target, an `intake` folder or `backup.target`) and `include` (an array of selections, each an array of `search --field` predicates: all predicates of a selection must hold, and a page that fits any selection is exported; there is no "everything"). Optional: `frontmatter` (`minimal`: only the export marker; `summary`, the default: also `title`, `type`, `summary` and `modified` where the page has them; `full`: the page's whole frontmatter), `links` (`relative`, the default: a wikilink to an exported page becomes a relative Markdown link; `text`: plain text; a link to a page that is not exported is always plain text) and `after_publish` (default false: refresh this target after every `publish` that committed). The handler `command` takes `command` (required: the name of an entry of `commands`). A field the handler does not take is an error. |
+| `targets` | checkout, gate | object | yes | - | Target name (lower-case letters, digits and hyphens) to target; the name is the argument of `export run`. Every target has `handler` (`markdown`: the pages as Markdown files; `command`: the same Markdown run through a converter of this checkout), `path` (an absolute path outside the instance; it must not lie in or contain another target or an `intake` folder, and not be, lie in or contain `<backup.target>/git` or `<backup.target>/<machine>`, nor lie in any other machine's folder or a bare repository) and `include` (an array of selections, each an array of `search --field` predicates: all predicates of a selection must hold, and a page that fits any selection is exported; there is no "everything"). Optional: `frontmatter` (`minimal`: only the export marker; `summary`, the default: also `title`, `type`, `summary` and `modified` where the page has them; `full`: the page's whole frontmatter), `links` (`relative`, the default: a wikilink to an exported page becomes a relative Markdown link; `text`: plain text; a link to a page that is not exported is always plain text) and `after_publish` (default false: refresh this target after every `publish` that committed). The handler `command` takes `command` (required: the name of an entry of `commands`). A field the handler does not take is an error. |
 | `commands` | checkout, names a command | object | no | `{}` | Command name to command: an array of the program and its arguments, run by the `command` handler without a shell, with stdin closed and a timeout of 300 s. The last two arguments appended are the directory holding the Markdown and an empty output directory. Exit 0 makes the regular files in the output directory the target's content; anything else leaves the target unchanged and prints the end of the program's stderr. |
 
 - **Absent:** No export: `export run` stops with exit 1 naming the section, `publish` exports nothing and `doctor` reports `OK`.