Layout misclassifies dotted poetic line as formula, export leaves text empty

### Bug

A **poetic line with dot leaders** (`................ жизни картиновой ................ понесло Константиново ».`) is **misclassified as `formula`** by the layout model (OCR text with ellipsis, not a math formula).

The block is exported as `FormulaItem` with OCR text in `orig`, but **`text` is empty / missing**. Parse returns **success**, yet `json_content` fails `DoclingDocument.model_validate_json()`. Chunking then fails: `Input document parsed.json is not valid.`

Setting `text` from `orig` fixes validation and chunking.

**Root cause (as seen downstream):** classification error → invalid schema export.

### Steps to reproduce

1. Parse attached **1-page PDF** ([misprocessed.pdf](https://github.com/user-attachments/files/29854351/misprocessed.pdf), poetic excerpt with dot leaders)
2. In `json_content`, find item with `"label": "formula"` and dotted Russian text in `orig`, no `text`.
3. Validate: ```python
from docling_core.types.doc import DoclingDocument
DoclingDocument.model_validate_json(open("parsed.json", "rb").read())
```
→ fails (`text` required on formula item).
4. Chunk same JSON via `/v1/chunk/hybrid/source/async` (`from_formats: ["json_docling"]`) → 0 chunks.
5. Add `"text": ""` → validation and chunking succeed.

Parsing options used:

```
{
"do_ocr": false,
"do_formula_enrichment": false,
"do_code_enrichment": false,
"to_formats": ["json", "text"]
}
```

**Minimal fragment:**
```json
{
"self_ref": "#/texts/5",
"parent": {
"$ref": "#/body"
},
"content_layer": "body",
"label": "formula",
"prov": [omitted],
"orig": "..................... жизни картиновой ..................... понесло Константиново »."
},
{
"self_ref": "#/texts/6",
"parent": {
"$ref": "#/body"
},
"content_layer": "body",
"label": "text",
"prov": [omitted],
"orig": "(Восп., 2, 131)",
"text": "(Восп., 2, 131)"
},
```

**Expected:** classify as text/paragraph; if labeled `formula`, populate `text` (e.g. from `orig`) so export passes schema validation.

### Docling and Python versions

`docling-serve` output:

```
Docling version: 2.107.0
Docling Core version: 2.85.0
Docling IBM Models version: 3.13.3
Docling Parse version: 7.2.0
Python: cpython-312 (3.12.13)
Platform: Linux-6.18.33.2-microsoft-standard-WSL2-x86_64-with-glibc2.34
```

**Attachments:** 1-page PDF + JSON fragment above.

Reproduce the issue with the attached 1-page PDF and the listed parsing options, then inspect the formula item in json_content. Start with DoclingDocument.model_validate_json() and the /v1/chunk/hybrid/source/async endpoint to trace why the exported item lacks text. Done means the poetic line is classified as text, or a formula export includes text from orig, so JSON validation and chunking succeed.

Written by the indexing model from the issue text.