feat(cli): auto-detect aspect_ratio from composition dims when --aspect-ratio is omitted (#1145)

When the user runs `hyperframes cloud render` without `--aspect-ratio` and
the project source is a local directory, parse the entry HTML's root
`<div data-composition-id ...>` for `data-width` / `data-height` and pick
the supported aspect ratio that matches within ±0.05 tolerance:

- 16:9 (≈1.778) ← landscape 1920×1080, 4K 3840×2160, etc.
- 9:16 (≈0.563) ← portrait 1080×1920
- 1:1 (=1.0)    ← square 1080×1080

If the composition's ratio matches one of these, the CLI sets
`aspect_ratio` in the submit body and prints a one-line note
(`Detected aspect ratio: 9:16 (from index.html dims 1080×1920)`).

If the composition has no root div, no dims, or a ratio outside all three
tolerance bands (e.g. 4:5, 5:4, 21:9), the CLI logs a one-line warning
explaining the fallback and leaves `aspect_ratio` out of the submit body
— the server defaults to 16:9, and the user can pass `--aspect-ratio`
explicitly to override.

Explicit `--aspect-ratio` always wins. Detection is skipped for
`--asset-id` / `--url` project sources since the composition isn't on
disk; user gets a brief note in that case too.

New helper: `packages/cli/src/cloud/detectAspectRatio.ts` (pure regex
parse, no DOM library dep). 23 tests cover canonical matches, in-band
tolerance, all three non-match patterns (no root div, no dims, ratio out
of bands), and authoring edge cases (unquoted attrs, attribute order,
self-closing tags, multi-composition files).

Closes the `auto` carve-out flagged in ef#38182's deferred-scope note —
the CLI gets auto-detect without requiring a server-side zip-parse
capability (no API change).