feat(canary): honeydoc_docx + honeydoc_pdf generators

honeydoc previously emitted HTML only — operators picking 'Document'
out of the dropdown got a .html file dropped at /Documents/
quarterly_report.docx, which any attacker would clock the moment they
ran 'file' on it.

Two new generators that emit the real artifact format:

- honeydoc_docx: stdlib zipfile only. Builds a minimal but valid
  Office Open XML zip with the same Q3 review body as the HTML
  flavor and an external-image relationship pointing at the
  callback URL — same trick the operator-upload DOCX instrumenter
  uses, fetched on document open by Word and LibreOffice. Reuses
  _drawing() and _next_rid() from instrumenters/docx.py to keep
  the body/relationships shape identical between synthesised and
  instrumented files.

- honeydoc_pdf: pikepdf-backed. One-page PDF in the 14 base fonts
  (Helvetica, no font embedding), realistic body, /OpenAction /URI
  on the catalog so most viewers fire the callback on document
  open. Falls back to a clear error if pikepdf is missing so the
  operator can switch to honeydoc / honeydoc_docx.

Default placement paths now reflect each generator's true extension
(.html / .docx / .pdf) so the UI suggests something sensible. Both
generators surfaced in the New Token modal's generator dropdown.

decnet/canary/paths.py

@@ -25,7 +25,9 @@ _LINUX_DEFAULTS: dict[str, str] = {
     "env_file": "/home/{user}/.env",
     "ssh_key": "/home/{user}/.ssh/id_rsa",
     "aws_creds": "/home/{user}/.aws/credentials",
-    "honeydoc": "/home/{user}/Documents/quarterly_report.docx",
+    "honeydoc": "/home/{user}/Documents/quarterly_report.html",
+    "honeydoc_docx": "/home/{user}/Documents/quarterly_report.docx",
+    "honeydoc_pdf": "/home/{user}/Documents/quarterly_report.pdf",
 }
 
 _WINDOWS_DEFAULTS: dict[str, str] = {
@@ -33,7 +35,9 @@ _WINDOWS_DEFAULTS: dict[str, str] = {
     "env_file": "/home/{user}/Desktop/prod.env",
     "ssh_key": "/home/{user}/.ssh/id_rsa",  # OpenSSH on Windows uses the same path
     "aws_creds": "/home/{user}/.aws/credentials",
-    "honeydoc": "/home/{user}/Documents/quarterly_report.docx",
+    "honeydoc": "/home/{user}/Documents/quarterly_report.html",
+    "honeydoc_docx": "/home/{user}/Documents/quarterly_report.docx",
+    "honeydoc_pdf": "/home/{user}/Documents/quarterly_report.pdf",
 }