fix(seo): move top-level robots into metadata block (2 files)

[bblietz]

What

Two files had a top-level robots: index key and no metadata: block, diverging from the canonical frontmatter shape used in 547 of 582 docs pages:

• docs/The Roku Channel/video-on-demand/title-avail-specifications.md
• docs/The Roku Channel/live-linear/ovp-linear-ingest-spec.md

This PR moves robots into a stub metadata: block in the canonical key-order position, so the SEO frontmatter backfill pipeline can populate metadata.title/metadata.description without producing duplicate robots: keys.

Diff

2 files changed, 8 insertions(+), 2 deletions(-). Each file: removed the top-level robots: index line; inserted a 4-line stub metadata: block in canonical position (after hidden:, before any closing). No other content modified.

Verification

Before: top-level robots: present, no metadata: block. The SEO snapshot tool flagged both as top_level_robots without metadata block.
After: top-level robots: removed, metadata: block in canonical position with robots: index inside. Both files match the canonical 547-of-582 frontmatter shape.

Context

This is PR #0a of an SEO frontmatter backfill effort that will populate metadata.title, metadata.description, and excerpt across all ~582 docs pages over a series of follow-up PRs. PR #0a fixes a corpus pre-condition (alongside PR #0 which removed a duplicate frontmatter block in ad-requirements.md).

🤖 Generated with Claude Code

[bblietz]

Closing as redundant: the top-level robots: cleanup is already reflected on v2.0 (no top-level robots: key in the affected files). Some files this PR touched have also been deleted upstream, making the diff stale.

[bblietz]

Re-opened: I closed this prematurely. The 2 Roku Channel files (ovp-linear-ingest-spec.md and title-avail-specifications.md) still have top-level robots: keys on v2.0; only the unrelated upstream changes touched files that this PR's stale base showed as deletions. The actual commit (1a760f5) only modifies those 2 files and the change is still needed for the SEO backfill pipeline.