ci: refactoring some things and removing others

Lots of source additions here from long-standing notes over the past few
months. Squashed to make it neater than 219 commits.

- bump version to v1.2.4, Jun 2026
- expand Tor section with new "Traffic analysis and the limits of Tor" subsection
  guard node persistence, website fingerprinting, and a practical breakdown of
  when Tor is and is not sufficient
- expand hardware/firmware threat section with new subsections on firmware
  implants, USB attack hardware (O.MG Cable, Rubber Ducky), Evil Maid attacks,
  supply chain compromise, and a physical inspection checklist
- rename "Removing Metadata from Files/Documents/Pictures" section to "Metadata
  auditing"; add reference table of tools by file type; expand EXIF/XMP coverage,
  PDF metadata (font fingerprinting), and DOCX revision history with real-world
  source identification cases; restructure subsections
- add introductory paragraph to "Your Metadata" section
- add new appendix B8: operational security failure case studies with common
  threads
- add new appendix B9: post-quantum cryptography covering HNDL threat, NIST PQC
  standards, Signal's PQXDH, browser hybrid KEM, PGP limitations, VPN guidance,
  and Monero note
- add new appendix C1: stylometric analysis and writing style covering features
  measured, deployed tools, real cases (J.K. Rowling), effective and ineffective
  countermeasures including AI rewriting
- fix Dangerzone GitHub URL (firstlook -> freedomofpress)
- Remove duplicate footnote [^500]; minor wording fixes ("users" -> "people",
  passive voice tweaks, cross-reference updates)

- docs/index.md: both MSK and RSK GPG fingerprints in a collapsible tip admonition
  instead of bare text
- docs/about/index.md: convert Note admonitions to tip; reformat social media
  links into collapsible tip block
- docs/mirrors/index.md: simplify PDF download instructions to point to Releases;
- README.md: add star history chart
- mkdocs.yml: rename site to "The Hitchhiker's Guide"; update site description
  with hashtags

- sign.yml: remove commented-out workflow_run trigger and if: condition; add
  verify job that runs after sign, downloads artifacts, runs verify_pdf.py, and
  writes a full job summary with hashes; update artifact upload description; minor
  comment and whitespace cleanup
- release.yml, changelog.yml: replace decorative banner comments with single-line
  comments; fix trailing-space style in permissions block
- publish.yml: remove stale comment about nomaterial theme
- verify_pdf.py: full rewrite: replace single-hash-file lookup with flexible
  resolver that checks both bare hash files (.sha256, .b2sum) and two-column
  sumfiles (sha256sums.txt, b2sums.txt); add BLAKE2b verification alongside
  SHA-256; fix signature extension (.asc not .sig); improve CLI (--file,
  --export-dir flags; remove --all; default runs all checks); improve VirusTotal
  output with direct link; cleaner output formatting with ruled separators

docs/mirrors/index.md

@@ -17,7 +17,7 @@ schema:
 
 ---
 
-!!! Note "Where to find the Hitchhiker's Guide"
+???+ tip "Where to find the Hitchhiker's Guide"
 
       -   [Original](https://anonymousplanet.org)
       -   [Tor v3](http://thgtoa3jzy3doku7hkna32htpghjijefscwvh4dyjgfydbbjkeiohgid.onion) **Down**
@@ -27,9 +27,7 @@ schema:
 
 !!! Note "PDF export (single file)"
 
-    The guide is also available as a **PDF** (images and layout preserved). It is built automatically in GitHub Actions: open [**Build guide PDF**](https://github.com/Anon-Planet/thgtoa/actions/workflows/build-sign-release.yml) on the [**source repository**](https://github.com/Anon-Planet/thgtoa), pick a successful run, and download the **`thgtoa`** and **`thgtoa-dark`** artifacts. You can start a fresh build anytime (**Actions** → **Build guide PDF** → **Run workflow**).
-
-    To produce the same file locally, clone the repository and run `python3 scripts/build_guide_pdf.py --both` (Python, [MkDocs Material](https://squidfunk.github.io/mkdocs-material/getting-started/), and **Google Chrome** or **Microsoft Edge** required). More detail is in the [repository README](https://github.com/Anon-Planet/thgtoa#ways-to-read-or-export-the-guide).
+    The guide is also available as a **PDF** (images and layout preserved). It is built automatically. See the [Releases](https://github.com/Anon-Planet/thgtoa/releases). More detail is in the [repository README](https://github.com/Anon-Planet/thgtoa#ways-to-read-or-export-the-guide).
 
 !!! Note "Our official git mirrors"