wardethan2000-eng puts Word-style editing inside Mike

Adds an always-on editor for .docx documents in the viewer: click and
type in the rendered document, a toolbar for bold/italic/underline and
alignment, and autosave a moment after you stop typing. Formatting is
written back into the real .docx, so the letterhead, header, footer,
fonts and signature block are preserved.

Backend (docxTrackedChanges.ts + routes/documents.ts):
- applyFormattedEdits: reconciles edited paragraphs (runs with
  bold/italic/underline/colour/size + alignment) against the current
  document, rebuilding only changed paragraphs and inheriting each
  paragraph's base run properties so fonts carry over.
- edit_document now adds and removes whole paragraphs (a blank line in
  the replacement starts a new paragraph; deleting a paragraph's text
  removes it) via tracked paragraph marks; new column document_edits.mark_w_ids.
- applyUserParagraphEdits (inline text reconcile) and a save-docx
  autosave target.
- New routes: /formatted-edit, /inline-edit, /save-docx, /paragraphs;
  each saves a user version (overwrites the working copy in place, or
  starts a fresh version on top of an upload/assistant edit).

Frontend:
- RichDocxEditor: always-on contentEditable on the rendered document,
  formatting toolbar, debounced autosave; DocPanel routes document-mode
  .docx to it.

Also: golden-rule letter drafting guidance in the assistant prompt.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018RCY6K4dNwdbo9gU3HQ9un

Extends the in-app Word editor with the formatting controls a letter
actually needs, all written back into the real .docx:

- Text colour and font size, applied to the selected text. Only text the
  user styled carries colour/size - the serializer reads them from spans
  the toolbar marked rather than from computed style, so untouched text
  keeps the document's own formatting.
- Heading 1-3 via a paragraph-style dropdown, applied as w:pStyle so Word
  treats them as real headings (navigation pane, outline level). Choosing
  "Body text" clears the style again.
- Heading styles the document does not define are added to styles.xml
  with a sensible default; a document that already defines them (a firm
  template) keeps its own look untouched.

Verified end to end in the browser: colour and Heading 2 both persisted
into the saved document, with the heading style defined and text intact.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018RCY6K4dNwdbo9gU3HQ9un

Lists: a paragraph can be marked as a bullet or numbered item. The list
definitions are written into word/numbering.xml and the part is registered
in the package when a document has none, so Word renders the list. A
document that already defines its own numbering keeps it - ours is added
beside it with unused ids. Consecutive items of the same kind share one
numId, so a numbered run counts 1, 2, 3. Clearing the list removes w:numPr.

Undo: POST /single-documents/:documentId/undo-edit restores the bytes of
the version preceding the current one and makes that current, so a save
can be stepped back without destroying later history.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018RCY6K4dNwdbo9gU3HQ9un

Adds the toolbar controls for the list and undo support already in the
engine: bulleted list, numbered list, and an undo button that steps the
document back to how it was before the last save.

The list buttons toggle - pressing the same one again turns the
paragraphs back into ordinary text. A paragraph the document already
renders as a list item (inside a ul/ol) is recognised as one, so an
existing list is not flattened to body text by the next save. Undo
re-fetches and re-renders the restored document.

Verified end to end in the browser: a bulleted list persisted into the
saved .docx as a real Word list (w:numPr + numbering definitions
registered in the package), and undo restored the previous version
without destroying the later one.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018RCY6K4dNwdbo9gU3HQ9un