DOC-7104: Migrate content/operate/rs/7.4/references/ (incl. rest-api) to render hooks - #4094

…o slash

The original regex required `/` or end-of-string right after the mount
name, so a link like `/commands?group=cluster` (no trailing slash before
the query) silently passed through unchecked -- this tool's own blind
spot, found the hard way: human review caught it by hand on DOC-7104
PR #4093, and the identical instances recurred in #4094/#4096/#4098
before this fix existed to catch them.

Also reconsiders the `/commands` special case: it has no backing
_index.md on disk, so _find_content_file always reports it unresolvable,
but Hugo auto-generates a section page for the directory and GetPage
finds it anyway (confirmed by building both /commands?group=x and
/content/commands?group=x and comparing rendered hrefs -- identical).
Review wanted the canonical form applied there too, so it's now
hardcoded as FIXABLE instead of silently skipped.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

…w pattern as #4094)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

…r hooks

Converts relref link shortcodes and note/tip/warning/alert callout
shortcodes to render-hook equivalents across content/operate/rs/7.4/,
excluding references/ (done separately in #4094) -- 145 of 162 files,
936 relref links and 155 callouts.

Found and fixed the recurring indented-callout bug (27 files, ~30
blocks) and the recurring HGETALL missing-paren relref in
databases/connect/troubleshooting-guide.md (3rd version to carry it:
live tree, 7.22, now 7.4). Flagged, not fixed: 6 pre-existing broken
relref targets in new-features-redis-enterprise.md (draft: true, never
renders) -- same 6 targets that recur in every version.

Review (round 2) caught three more issues, all fixed -- same as #4095:
- Bare /commands links in _index.md and
  security/access-control/redis-acl-overview.md, missing the /content/
  prefix (confirmed identical rendered href either way).
- new-features-redis-enterprise.md's 6 dead links: applied the same
  /content/ prefix for consistency. Cosmetic only -- none of the 6
  targets exist regardless of prefix.
- databases/import-export/flush.md: the port-configurations link's
  anchor was a stray old absolute URL concatenated into the fragment,
  predating this migration. Replaced with the real heading slug.

Verified via build/diff_rendered_hrefs.py: after filtering the known
CSS-asset-fingerprint noise from comparing builds in two different
worktree environments, the only real content change is the corrected
flush.md anchor -- everything else confirmed 0 diff.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

migrate_shortcode_links.py's linkify stage correctly canonicalizes almost
every converted link to /content/<path>.md[#anchor], but a link that
gets a manual post-hoc text fix after the pipeline already ran (e.g.
inserting a separator slash a relref-plus-literal-suffix concatenation
was missing) never gets a second pass through linkify. The result is a
bare /operate/... path that resolves to the exact same rendered href as
the canonical form, so build/diff_rendered_hrefs.py -- this migration's
usual verification -- is blind to it by construction.

Found on PR #4086 (release-notes/ unit): human review manually flagged 8
malformed links; a corpus-wide grep for the same shape found 21 across 9
files (13 more than manual review caught), plus 8 more that turned out
to be genuinely pre-existing dead links in the identical shape, invisible
to any prior check since Hugo's relref shortcode only ever validated its
own target, never text concatenated onto it afterward.

check_uncanonicalized_links.py reuses migrate_shortcode_links.py's own
resolver (_find_content_file) so a --fix run applies the exact same
rewrite the pipeline would have. Three outcomes: FIXABLE (resolves,
--fix rewrites it), MOUNT_ONLY (resolves only through a Hugo module
mount -- never auto-fixed, same rationale _find_content_file already
documents for not following mounts on a rewrite), DEAD (doesn't resolve
at all -- reported only, never guessed).

A second commit fixed the tool's own blind spot, found immediately on
its first real use: the original MOUNT_PREFIX_RX required a `/` or
end-of-string right after the mount name, so a bare `?query`/`#fragment`
with no slash before it (e.g. /commands?group=x) silently passed through
unchecked -- exactly the shape human review caught by hand across
DOC-7104 PR #4093/#4094/#4096/#4098. Also reconsidered the `/commands`
special case: it has no backing _index.md on disk so the filesystem
resolver always calls it unresolvable, but Hugo auto-generates a section
page for the directory and GetPage finds it anyway (confirmed by
building both /commands?group=x and /content/commands?group=x and
diffing rendered hrefs -- identical). Now hardcoded as FIXABLE instead
of silently skipped.

Verified against the pre-fix state of PR #4086: reproduces the exact
21 FIXABLE / 8 DEAD split. A full-corpus scan of content/ elsewhere
comes back to 3 unrelated hits, confirming it isn't noisy. 8 unit tests
cover both commits' behavior.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>