fix(const)!: name LLACode codes 0 and 2 as RFC 5568 does (#1848)

[JarryShaw]

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---

• Rename LLACode.Wilcard to Wildcard and LLACode.MH to MN, in the
  hand-written vendor table and the generated module alike. No alias keeps
  either old name: this is a breaking rename.
• Give the LLACode crawler its own template, so the generated class
  docstring carries a versionchanged:: 1.5.0 note on both renames; the
  const docs page carries the same note.
• Point the MH-LLA option reader and builder, and their unit tests, at
  LLACode.MN.
• Pin the new names, the absence of the old ones, and that the crawler
  renders the committed module byte for byte.

Closes #1848

Breaking: LLACode.Wilcard and LLACode.MH are gone with no alias, following the ruling on #1848 and the precedent of #1090 and #1715. LLACode now carries its own copy of the generator template, so that the class docstring can hold the rename note. That is the same pattern used for tcp/flags, http/status_code and ipv6/extension_header.

[JarryShaw]

Verdict: GOOD TO GO at 660669d15. A Sonnet cross-review (author: Opus) confirmed:

• No LLACode.Wilcard, LLACode.MH or Enum_LLACode.MH survives in pcapkit, tests, docs, examples, util or the changelogs.
• The copied LINE differs from vendor.default.LINE only by the rename note, which is the same pattern as ftp/command, http/status_code and tcp/flags.
• Running the real Vendor.__init__ offline renders a module byte-identical to the committed const/mh/lla_code.py.
• RFC 5568 §6.4.3 names code 0 Wildcard… and code 2 Link-Layer Address of the MN.
• The new tests fail on main's files.

Non-blocking:

• the rename note renders twice on the docs page (page and autoclass), as fix(protocols)!: rename OSPF_CrytographicAuthentication and group OSPF under the application layer #1090's did;
• :func: for LINE should be :data:;
• a few test docstrings still list LLACode among the default-template registries.

[JarryShaw]

for vendor/const templates, no need to mention the version directives. they're meant to be updated automatically by the scripts so no version changed/added are necessary.

[JarryShaw]

Understood. The scripts regenerate the vendor templates and the pcapkit/const/** files, so those get no version directives. I'll remove the versionchanged this PR adds to pcapkit/vendor/mh/lla_code.py and to the generated pcapkit/const/mh/lla_code.py. The note on the hand-written docs/source/pcapkit/const/mh.rst page stays, unless you'd rather drop that too.

Templates on main already carry such directives: ftp/command, http/method, ipv6/extension_header, pcapng/option_type, pcapng/tls_key_label, reg/apptype and tcp/flags, each mirrored in its const file. I'll file a follow-up to remove those as well. The #: notes on MAX_RETRY and PCAPKIT_CI_MODE in vendor/default.py document the crawler framework's own settings, not a template, so they stay.

[JarryShaw]

Verdict: GOOD TO GO at 5003607bc. A Sonnet cross-review checked the version-directive removal made per your ruling.

• The deleted LINE template and context override matched vendor/default.py's, except for the directive. Run offline, the crawler renders the committed const/mh/lla_code.py byte for byte, now through the shared default.
• Against main, the vendor and const files differ only by the renames to Wildcard = 0 and MN = 2. The MH reader and builder use LLACode.MN.
• No version directive remains under pcapkit/vendor/** or pcapkit/const/**. The note on the hand-written docs/source/pcapkit/const/mh.rst page matches RFC 5568 section 6.4.3.
• The tests that now pin the directive's absence fail if one is added back. The rename tests fail on the base.
• test_mh_unit.py gave 52 passed; test_tier_guard.py and test_const_enum_no_mint.py also pass.

[github-actions]

Coverage: 90.05% (unit tier, Python 3.15, 5003607bc, Unit Tests run success)

Package	Statements	Missed	Branches	Partial	Cover
pcapkit (top level)	104	2	20	2	96.77%
pcapkit/const	19595	881	2618	867	92.11%
pcapkit/corekit	2462	69	780	35	96.55%
pcapkit/dumpkit	276	3	100	3	98.40%
pcapkit/foundation	2914	164	1016	34	93.59%
pcapkit/interface	138	7	52	5	93.68%
pcapkit/protocols	17406	224	4580	189	98.10%
pcapkit/toolkit	872	177	298	8	77.18%
pcapkit/utilities	512	2	158	4	99.10%
pcapkit/vendor	4407	2342	1010	157	43.27%

Per-file detail: the coverage-html artifact of this run.