docs: add MODULE.md + MODULE.de.md inline docs

Studio reads MODULE.md / MODULE.<locale>.md from the installed
bundle and renders it in the module-detail Documentation
section. text-extract ships them now — EN+DE peers, same
schema as the README but trimmed for the in-app reader.

Signed-off-by: flemming-it <sf@flemming.it>

MODULE.md

@@ -0,0 +1,92 @@
+# text.extract
+
+Plain-text extraction from PDF and DOCX documents. Pure-Rust,
+in-WASM, no permissions required. The canonical first step in
+any flow that needs raw text — anonymise, summarise, translate,
+LLM-classify, audit-redact.
+
+## Capability
+
+- `text.extract@0.1.0`
+
+## Inputs
+
+| Name       | Type  | Description                                            |
+| ---------- | ----- | ------------------------------------------------------ |
+| `document` | bytes | The document to extract. Accepted MIME types below.    |
+
+Accepted MIME types (declared in `module.yaml#accepts_mime`,
+read by Studio as the file-picker filter):
+
+- `application/pdf`
+- `application/x-pdf`
+- `application/vnd.openxmlformats-officedocument.wordprocessingml.document`
+
+Other MIME types are rejected with a `invalid_input` error
+before any parsing happens.
+
+## Output
+
+| Name        | Type | Description                                       |
+| ----------- | ---- | ------------------------------------------------- |
+| `extracted` | json | `ExtractedDocument` schema below.                 |
+
+```json
+{
+  "engine": "pdf-extract",
+  "engine_version": "0.7",
+  "pages": [
+    { "number": 1, "text": "…" }
+  ]
+}
+```
+
+Per-page `confidence` and `bbox` fields are reserved in the
+schema for a future service-mode variant (pdfium / mupdf via
+host services) that surfaces layout information. v0.1.0 does
+not populate them; the schema accepts them as optional.
+
+## Permissions
+
+None. Pure-Rust pipeline (`pdf-extract`, `zip`, `quick-xml`).
+No filesystem, no network. The empty `permissions: []` in
+`module.yaml` makes that explicit; the hub enforces it.
+
+## Limits in v0.1.0
+
+- **Layout-naive PDF.** Multi-column or table-heavy documents
+  may produce reordered text. Single-column body text is solid.
+- **No OCR.** Scanned (image-only) PDFs return empty text per
+  page. Pair with a future `text.ocr@^0` step for those.
+- **DOCX-only Office.** `.doc` (legacy binary), `.rtf`, `.odt`
+  are not yet supported.
+
+Bumping to `1.0.0` requires either the service-mode variant
+(pdfium-quality output + layout) or a confirmed-good extraction
+score on a representative corpus.
+
+## Example flow
+
+```yaml
+name: extract-anonymise
+inputs:
+  document: bytes
+steps:
+  - id: extract
+    use: text.extract@^0
+    with:
+      document: $inputs.document
+  - id: redact
+    use: text.anonymize@^0
+    with:
+      text: $extract.extracted.pages[*].text
+outputs:
+  redacted: $redact.anonymized
+```
+
+## Build
+
+```bash
+cargo build --release --target wasm32-wasip2
+# Output: target/wasm32-wasip2/release/text_extract.wasm
+```