orb(content-lane): canonicalize issue-body path tokens in `checkContentLaneDeliverable

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⚠️ Definition of Done: this issue must be completed in full, in a single PR. Do not split this
work across multiple PRs, and do not defer any Deliverable below to a follow-up issue. A PR that
satisfies only some of the Deliverables, stubs a required test, or leaves a checkbox
partially-done does NOT resolve this issue and will be closed.

Context

checkContentLaneDeliverable (src/review/content-lane/registry-logic.ts:919-936) is the
deterministic "did this PR actually deliver the content file its linked issue names?" check — the guard
against a test-only PR closing a content issue via a bare Closes #N. It compares two things against
the same predicate:

const matchesSpec = (candidate: string): boolean =>
  spec.entryFilePattern.test(candidate) || (spec.providerFilePattern?.test(candidate) ?? false);
const mentionedPath = extractPathTokens(issueText).find(matchesSpec);              // :929  RAW token
…
const delivered = changedFiles.some((file) => matchesSpec(canonicalize(file)));    // :932  canonicalized

entryFilePattern/providerFilePattern are compiled by globToRegExp
(packages/loopover-engine/src/signals/change-guardrail.ts:82-103), which canonicalizes the glob
first (canonicalize lowercases, packages/loopover-engine/src/signals/change-guardrail.ts:11-13) and
emits new RegExp("^…$") with no i flag. So the compiled pattern only ever matches lowercase
input.

Result: an issue body that writes the path with any capitalization — Registry/subnets/foo.json,
registry/Subnets/Foo.json — produces no mentionedPath. With no issueTitleImpliesEntryPattern
configured (or a title that doesn't match it), checkContentLaneDeliverable returns
{ verdict: "not-applicable" }, and the deliverable gate silently does not run for that issue —
the exact "test-only PR closes a content issue without ever delivering the content" gap the function's
own header (src/review/content-lane/registry-logic.ts:875-882) says it exists to close.

classifyRegistryPrScope in the same file already documents why this matters
(src/review/content-lane/registry-logic.ts:778-781): "globToRegExp compiles the spec patterns against
a CANONICALIZED path … so match on canonicalize(f), or an uppercase / ./-prefixed / backslash-separated
changed path silently fails to classify as a registry submission." The issue-body side never got that
treatment.

Requirements

• checkContentLaneDeliverable must apply canonicalize to each token from extractPathTokens before
  testing it with matchesSpec, exactly as it already does for changedFiles.
• mentionedPath reported in the "missing" verdict must remain the original, non-canonicalized
  token as written in the issue body — it is rendered into the public PR comment and must match what
  the contributor and maintainer can see in the issue.
• Behaviour for an already-lowercase path token must be byte-identical to today.
• No change to extractPathTokens, globToRegExp, canonicalize, or the issueTitleImpliesEntryPattern
  fallback.

⚠️ Required pattern: mirror classifyRegistryPrScope's matchesPattern helper
(src/review/content-lane/registry-logic.ts:782), which canonicalizes the candidate at the point of
test while keeping the original string for anything user-visible. What does NOT satisfy this issue:
adding an i flag to the compiled globs (that changes guardrail matching repo-wide, which is a
separate, load-bearing behaviour); lowercasing inside extractPathTokens (that would also corrupt the
reported mentionedPath); or canonicalizing the whole issueText before tokenizing.

Deliverables

• checkContentLaneDeliverable in src/review/content-lane/registry-logic.ts returns
  { verdict: "missing", mentionedPath: "Registry/Subnets/Foo.json" } for an issue body naming
  Registry/Subnets/Foo.json against a PR that changed no matching file — asserted by a new named
  case in test/unit/content-lane-registry-logic.test.ts.
• The same test asserts the "delivered" verdict for that mixed-case issue body when the PR DOES
  change registry/subnets/foo.json.
• A test asserts the existing all-lowercase path behaviour (both delivered and missing) is
  unchanged.
• A test asserts an issue body naming a path that matches NO spec pattern still returns
  not-applicable (the change does not over-broaden the match).

All Deliverables above are required in a single PR. A PR that satisfies only some of them — for
example canonicalizing the token (Deliverable 1) but also lowercasing the reported mentionedPath,
breaking the public-comment text — does not resolve this issue.

Test Coverage Requirements

This repo enforces 99%+ Codecov patch coverage, branch-counted, and vitest.config.ts's
coverage.include covers src/**/*.ts — this file is measured. Both arms of the
find(matchesSpec) outcome (a token that matches, and one that does not) need a test, as do both arms
of the mentionedPath ?? … fallback in the missing return.

Expected Outcome

The content-lane deliverable gate fires on an issue that names its target file with any capitalization,
instead of silently reporting not-applicable and letting a PR close a content issue without
delivering the content. The mentionedPath shown in the public comment still quotes the issue verbatim.

Links & Resources

• src/review/content-lane/registry-logic.ts:875-936 (the check), :777-800 (classifyRegistryPrScope, the pattern to mirror)
• packages/loopover-engine/src/signals/change-guardrail.ts:11-13, :82-103 (canonicalize / globToRegExp)
• test/unit/content-lane-registry-logic.test.ts

[linear-code]

JSO-6727