docs(adjudication): fix the anchor grammar and six 0003 details

[CameronBrooks11]

Adds an addendum to docs/adjudications/0003-anchors.md recording the
owner's decisions of 2026-10-16 on seven details that SPEC.md §12 listed
under Left open by 0003, and moves each into SPEC.md §11 as normative
text. No implementation and no conformance cases change.

What the addendum decides

	decided	SPEC
1	a record's frontmatter is exactly anchor: <json>, kind: …, status: … (or reply-to: "<id>", kind: comment for a reply). The anchor is a JSON object (RFC 8259) in one canonical form: keys base, leaf {type, nth, text}, span, prefix, suffix, then replace for a suggestion only; ", " and ": " spacing, nothing else; ", \, LF escaped as \", \\, \n; U+0000–001F, U+007F–009F, U+2028, U+2029, U+FEFF, U+FFFE, U+FFFF as lower-case \uXXXX; nothing else escaped. Anything not byte-for-byte in that form, or any other frontmatter line, is record-inconsistent	§11.1
2	pins: a line exactly pins:, then one - {"path": P, "blob": B} line per target, same canonical form, sorted by path by code point, no duplicates. path is the destination's part before #, as written. A malformed pins block refuses every transclusion in the referrer as record-inconsistent	§11.9
3	a table's text: reading 8's cells, each pipe in a cell written as backslash-pipe, joined by space-pipe-space and rows by \n, then NFC. The escape keeps two different tables from becoming copies	§11.2
4	of several longest chains, the one whose sequence of current-leaf indices is lexicographically smallest	§11.3
5	4·L ≥ T, 2·L < T, and 40·L₁·T₂ − 40·L₂·T₁ ≥ 3·T₁·T₂ for the 0.15 margin	§11.3
6	a short prefix or suffix must sit at the leaf's edge, or the occurrence is not a hit	§11.5
7	a transclusion path resolves from the referrer's directory (. dropped, .. pops); a path starting with / or whose first segment holds : is unresolvable-path, as is a .. above the repository root; a path naming no file is document-missing	§11.9, §11.10

The addendum also lists, as the owner's decisions on the precision, the
choices the seven rulings left to the write-up: byte-exact canonical JSON
(key order, spacing, escape set, 40/64-hex base, plain-decimal nth),
the exact record line set, reply-to as a JSON string with a reply
carrying kind: comment and no status, the pin block's rules, the \|
table escape, unresolvable-path, and the tie-break by current indices
(which differs from a base-order reading on a two-leaf swap). A transclusion
path is raw text, for resolution and for pins alike, and a - line after
the pins end, across only blank, indented or comment lines, refuses the
referrer's transclusions.

unresolvable-path is a new resolution reason (§11.10). §12 drops the six
items now decided, keeps the rest of the transclusion-details item, and
gains a list of new open items raised by these decisions.

Evidence for the claims in the text

• JSON and YAML 1.1 read the same values. 20,000 random anchors, with
  strings drawn from U+0000–00FF, U+2028, U+2029, U+FEFF, U+FFFE, U+FFFF,
  a combining mark, an astral character and YAML punctuation, written in
  the canonical form: json.loads and PyYAML 6.0.3 safe_load agreed on
  every one, and none contained LF or CR. For YAML 1.2, an independent run
  with js-yaml 4.2.0 and yaml 2.8.3 found 0 disagreements with JSON over
  20,000 anchors.

• The integer forms. Checked against Python Fraction on 200,000
  random draws with T up to 120: no disagreement. With floats,
  22/30 - 42/72 evaluates to 0.1499999999999999, so >= 0.15 is
  False where the exact answer is True.

• Pin merges, git 2.47.3, stock git merge of two branches off one base:

  change on each branch	result
  both add a pin in the same slot	conflict
  both append at the end	conflict
  adds on either side of one unchanged line	clean
  re-pin two adjacent lines	conflict
  re-pin two lines with one between	clean
  the same re-pin on both	clean
  different re-pins of one line	conflict

  So one line per target does not by itself stop two added pins from
  conflicting; the addendum says so, and sorting by path is what spreads
  additions apart. That a conflicted referrer is refused rests on the
  suite's reading 12, which the addendum names as a reading.

• The worked example in 0003 §3, rewritten canonically: its prefix
  is 31 code points with the leaf's start 31 before the span, and its
  suffix is 32.

Checks

$ just check
All checks passed!
$ just test
8 passed
$ just conform
0 failure(s) across 237 case(s) in the fixture tree
$ just tree
237 cases: 160 accept, 77 refuse
0 problem(s)

Not merged: this awaits review.