docs: cleanup Confluence-export link debris + add confluence-html-link lint rule

[bblietz]

Summary

Audit step 4 partial: kills the 11 known <Name>_<digits>.html Confluence-export link artifacts left over from the original Confluence-to-Markdown migration. Each was repointed at the current in-repo doc that supersedes the dead Confluence page.

The audit called these "not aliasable" but the human-readable filename prefix maps every target unambiguously to a file that exists in the repo today.

Link rewrites (3 files / 11 edits)

File	Line	Was	Now
DEVELOPER/core-concepts/xml-components/component-initialization-order.md	18	children_1608551.html	/docs/references/scenegraph/xml-elements/children.md
same	23	interface_1608549.html	/docs/references/scenegraph/xml-elements/interface.md
same	28	script_1608550.html	/docs/references/scenegraph/xml-elements/script.md
same	58	PosterGrid_1607203.html	/docs/references/scenegraph/list-and-grid-nodes/postergrid.md
same	66	Remote-Control-Events_1607636.html	../scenegraph-xml/remote-control-events.md
same	67	Scene_1607315.html	/docs/references/scenegraph/scene.md
DEVELOPER/core-concepts/xml-components/scenegraph-compilation.md	24	component_1608292.html	/docs/references/scenegraph/xml-elements/component.md
same	31	Scene_1607315.html	/docs/references/scenegraph/scene.md
same	32	OverhangPanelSetScene_1613108.html	/docs/references/scenegraph/sliding-panels-nodes/overhangpanelsetscene.md
same	34	Component-Initialization-Order_1611697.html	component-initialization-order.md (sibling file)
REFERENCES/brightscript/interfaces/ifpath.md	74	https://sdkdocs-archive.staging.web.roku.com/roAssociativeArray_1611481.html	/docs/references/brightscript/components/roassociativearray.md

Path-convention notes

9 of 11 use lowercase absolute paths (/docs/references/...) matching the proven-working pattern: all 226 working in-repo absolute links in the repo today use the lowercase form, and the renderer resolves them case-insensitively to the uppercase docs/REFERENCES/ filesystem.

2 use relative paths (the Remote Control Events and Component Initialization Order references): both source files are under docs/DEVELOPER/core-concepts/, and there are zero working /docs/developer/... precedents in the repo, so a sibling-relative path is the safer choice. Filesystem resolution confirmed for both.

New lint rule

.github/scripts/docs-lint/rules/links.mjs

Rule id: confluence-html-link (error)

Catches:

• Relative or absolute link targets matching <Name>_<digits>.html (anywhere in the URL path)
• External URLs to sdkdocs-archive.staging.web.roku.com/

Wired into index.mjs RULES array. Lint baseline preserved (same 3 pre-existing ifscreen.md findings as before; ZERO new errors after the sweep).

Test plan

• node .github/scripts/docs-lint/index.mjs -> 0 confluence-html-link errors after sweep
• All 11 rewrite targets verified to exist in the repo today (mapping confidence HIGH for every one; ambiguous case for "Remote Control Events" resolved by reading the surrounding context, which is about the focus chain and event flow -- not the onKeyEvent() API)
• Lint baseline preserved (3 pre-existing findings in ifscreen.md unchanged)
• CI run on this PR

Out of scope (deferred to follow-up PRs of audit step 4)

• 151 broken-prefix in-repo absolute links (/docs/developer-program/ 112, /dev/docs/ 19, /docs/specs/ 17, /docs/references/ 2, /trc-docs/ 1)
• 8 anchor mismatches in DEVELOPER/release-notes/index.md
• 55 unique dead/errored external URLs identified by HTTP HEAD pass
• 5 misc broken relative paths
• 2,855 doc:slug ReadMe-legacy links (separate Tier-2 future migration)

Related

Part of the May 16 audit cleanup plan (dev-doc-review-report-2026-05-16.md step 4 -- broken-link sweep). Step 1 (Quick Wins) is in flight as PR #52. Step 2 (BrightScript fence sweep + lint rule) is in flight as PR #54.