docs(foundation): second whole-repo pass over foundation (#1103)

[JarryShaw]

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• You will be asked some questions, please read them carefully and answer honestly

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• Followed the coding style (make pylint, make mypy, make isort)

• make test passes, and a test case covers the change. Narrow runs only, listed below.

• Added a changelog entry under docs/source/changelog/ and regenerated CHANGELOG.md, if the change is user-visible: N/A — centralised in docs(changelog): shared 1.5.0 changelog — long-lived, merges last (#610, #616, #617, #618, #620) #657

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Summary

#1103 second whole-repo pass, foundation slice.

Directives, 1.1.0-1.4.1 backfill (18, in 7 files):

• Extractor.reassembly/.trace raise UnsupportedCall when off (1.1.1);
  Extractor and extract() rename strict to reasm_strict (1.2.0).
• TraceFlow.register renamed register_dumper (1.2.0); register_port
  renamed register_apptype (1.3.1), both versionremoved.
• Engine, Reassembly, TraceFlow: metaclass-supplied name/protocol and
  registration at class definition (1.3.0).
• The Extractor and TraceFlowBase register_* methods take a descriptor
  or class; register_extractor_engine's engine is name; ext is
  keyword-only on the three dumper registrars (1.3.0).

Accuracy:

• IPv6._rectify_header names the four adapters that build IPv6 data.
• register_protocol states what Design: adopt the EnumMeta/EnumSchema opt-in registration pattern for Protocol, Engine, Reassembly and TraceFlow #514 did with the name key.

Rendered markup:

• Three utilities.config doc-comments split a role across their first
  line, which napoleon's NumPy pass ate; reflowed.

AST guard identical on all nine files; tests/project and the pinning
selections pass.

Refs #1103

[JarryShaw]

Verdict: GOOD TO GO at 0ca7713c0. A Sonnet cross-review (author: Opus) found no blocking findings. Scope stays inside the slice, the AST guard is identical against main, and every directive was checked against the release tags. The merged build of all nine second-pass heads has 18 warnings, the same as main. tests/project: 950 passed, 1 skipped, 3670 subtests passed..