docs: complete zupt → vaptvupt rename; README v4.0.0 refresh

- README: add 'What's new in 4.0.0' section, extend release history
  v2.2.4 → v4.0.0, fix stale section titles (benchmark/security/feature
  tables), point fast-install at short.securityops.co/vaptvupt, fix
  related-project links (vaptvupt-codec, libvuptsdk, real repo names)
- install.sh: clone the renamed repo, vaptvupt success message
- Rename remaining zupt → vaptvupt across INSTALL.md, DISTRIBUTION.md,
  SECURITY.md, THREAT_MODEL.md, ROADMAP.md, THIRD-PARTY-NOTICES.md,
  gui/ + sdk/ + packaging READMEs, doc/vaptvupt.1, spec comments/URLs
- New doc/vaptvupt-gui.1 (GUI 1.3.0, VAPTVUPT_BIN/ZUPT_BIN env vars);
  doc/zupt-gui.1 kept as hardlinked compat copy
- Deliberately unchanged: .zupt extension, ZUPT header magic,
  ZUPT-* crypto domain-separation constants, zupt_*/ZUPT_* code
  identifiers, libzuptsdk artifact names, legacy symlink notes,
  CHANGELOG/AUDIT historical entries, Provides/Obsoletes upgrade path
- tests/test_packaging_syntax.sh: THREAT_MODEL section titles updated

doc/vaptvupt.1

@@ -197,9 +197,9 @@ extreme (optimal parsing, ~5\(en10\(mu slower encode, best ratio).
 .B --codec \fIid\fR
 Force a specific codec by id. Accepted values:
 .BR store " (0x0000), "
-.BR zupt-lz " (0x0008), "
-.BR zupt-lzh " (0x0009), "
-.BR zupt-lzhp " (0x000A), "
+.BR vaptvupt-lz " (0x0008), "
+.BR vaptvupt-lzh " (0x0009), "
+.BR vaptvupt-lzhp " (0x000A), "
 .BR vaptvupt " (0x0010 — default), "
 .BR auto " (0xFFFF — pick at runtime)."
 
@@ -588,7 +588,7 @@ in the source distribution.
 Cristian Cezar Moisés <zupt@riseup.net> — primary author and maintainer.
 
 .SH BUGS
-Report bugs at https://git.securityops.co/cristiancmoises/zupt/issues
+Report bugs at https://git.securityops.co/cristiancmoises/vaptvupt/issues
 or by email to <zupt@riseup.net>.
 
 .SH LICENSE
@@ -605,7 +605,7 @@ available from <sac@securityops.co>.
 .BR cryptsetup (8),
 .BR jasminc (1).
 .PP
-Project home: https://git.securityops.co/cristiancmoises/zupt
+Project home: https://git.securityops.co/cristiancmoises/vaptvupt
 .br
 Threat model: see
 .B THREAT_MODEL.md