fix(annot): draw callouts upright on rotated pages - #5354

What this changes

Fixes #4686.

A callout on a page with /Rotate 90, 180 or 270 was laid out in user space and skipped the /PCTextRotate turn that text boxes already get, so the box looked sideways. A new callout now uses that same turn. Its leader and text box are mapped into the displayed frame, and the UI picks the leader side in view space.

Supersedes #4690. That branch no longer merges; the comments UI has since moved from comments.rs to tools/comments/composer.rs. This is the same behaviour on current main.

Existing callouts saved without /PCTextRotate keep their current look. Unrotated pages are unchanged.

How you verified it

• cargo test -p pdfcraft-annot callout — 4 passed, including callout_on_a_turned_page_is_drawn_upright_as_displayed and the three existing callout tests.

• cargo fmt -p pdfcraft-annot -p pdfcraft-ui-egui -- --check

• cargo fmt --check

• clippy with -D warnings on the crates I changed

• tests pass on the crates I changed

• cargo xtask layers and cargo xtask assets (no crate boundary or asset change)

Tests. crates/annot/src/tests.rs::callout_on_a_turned_page_is_drawn_upright_as_displayed adds a callout to a page with /Rotate 90 and checks /PCTextRotate, the form /Matrix, and that the leader starts at the pointed-at spot in the displayed frame.

Never-crash

• No new unwrap/expect/panic!/unreachable!/todo! outside tests, unless it is provably infallible with a comment saying why
• No indexing or slicing with input-derived positions (get, and strings only at char boundaries); checked or saturating arithmetic; allocations sized by input are capped; recursion is bounded
• No unsafe
• Any crash this fixes has a small synthetic regression test (not a crash; the regression test pins the sideways callout)

Provenance

• No asset from an Adobe product, and no Adobe icon recreated, traced or imitated
• No font files committed here (they live in storytold/craft-fonts)
• No GPL/AGPL code copied in. MuPDF, Ghostscript, Poppler, veraPDF and DSS may only be run as external oracle processes
• Behaviour comes from the specification or black-box observation, not from reading another implementation's source
• Every new asset has an ATTRIBUTION.toml entry and cargo xtask assets passes (no new asset)

Security

• --root confinement still holds on every path, including ones reached by nested tool dispatch
• MCP and the UI control channel stay opt-in, loopback-only and token-authenticated
• No new outbound network access (that decision is the owner's)

Parity and reach

• parity/acrobat-features.toml updated in this PR, with notes saying what is still missing. shipped means "exists and tested", not "as good as Acrobat"
• Reachable headlessly through an automation tool where that applies (AGENTS.md §3), so agents can drive it and not just the UI (comment_add / add_annotation sets /PCTextRotate from the page)
• Docs updated if this changes a documented behaviour (docs/, crate README) (parity notes only)

Anything a reviewer should look at first

• Callouts on turned pages now render upright as displayed. Existing callouts without /PCTextRotate are left alone.
• Unrotated pages, including a landscape MediaBox with /Rotate 0, are unchanged. /CL and /RD stay in user space.
• Draw callouts upright on pages with /Rotate #4690 is the earlier attempt at this fix and should be closed in favour of this branch.