fix(ui): validated signature display, snapshot tab reuse (#1895)

* fix(ui): validated signature display, snapshot tab reuse

Signature widgets with layered appearances baked the unverified state
into the page, so a valid signature kept reading 'Signature Not Verified'
while the banner and panel said valid. Validated verdicts are now drawn
into the icon and caption layers in the display copy only: the signed
bytes are untouched, saving keeps the original appearance, and files
without those layers or without a valid verdict render exactly as before.

Other valid signatures still get the verdict mark over their widget,
sharing one style with the Signatures panel, and hide it again once the
appearance itself shows the verdict.

View signed version and View revision opened a new tab on every click,
and every tab showed the document title, so repeats piled up identical
tabs. Repeats now reuse the snapshot tab, snapshot tabs read like their
source plus the suffix in the tab strip, window title and Combine picker,
and carry a notice bar naming the revision with a Close that asks about
saving first.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* Address review comments on validated appearances and trust refresh

Count every field when checking shared appearance streams, so a
caption shared with an unvalidated field is never rewritten for the
valid one alone.

Pick the icon slot by drawing instead of length, and only when a
single layer qualifies. Bare rectangles never count as the icon, and
ambiguous or missing slots fall back to the overlay badge.

Revalidate and invalidate together through one helper, so trusting a
certificate always drops rendered pages. Trust alone still marks
nothing dirty.

Tests: mixed-verdict sharing, longer decorative borders, competing
and doubled layers, capture-before preservation, trust invalidation
without zooming, and signed Session round trips with rendering,
saving and passwords.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* Prove the icon slot geometrically and cover real layered signatures

A lone line drawing is still not the icon: frames and borders span the
box while the status mark lives in a corner of it. The icon now has to
sit strictly inside the appearance frame and cover at most half of it;
anything else falls back to the overlay badge. Widgets without a
measurable frame veto the rewrite the same way.

Tests: parsed extents and inhabitant checks as units, both reported
border repros plus a frameless widget, and real layered signatures
built with cms::sign_detached through Session open, trust, rendering,
save and reopen, plain and password-protected.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* Identify the icon by shape instead of geometry

A lone line drawing is still not the icon, but size and position were
the wrong signals: the real status mark is large, and geometry blocked
it. Frames, borders and panels are rectangles by nature while the mark
is not, so a drawing made only of axis-aligned rectangles is decoration
however it is stroked. Singularity, shared-stream and template checks
are unchanged; anything ambiguous still falls back to the overlay badge.

Tests: rectangularity as a unit, nested line-drawn frames, and a
triangular fixture mark in place of the rectangular one.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* Budget the appearance walk and keep the marks with the bytes

The walk that finds a signature's icon and caption capped depth,
layers and fields, but not the work: a dictionary whose entries all
point at the next one is visited once per entry per level, so a small
hostile file never finishes opening. The walk now counts its visits
and gives up, and a field whose tree cannot be read to the end stops
the whole pass, because a layer we never read may be the one two
fields share and a rewritten shared layer puts one field's verdict on
another field's page. The sharing count is exact again with that: two
widgets of one field pointing at the same appearance claim it once,
or the field vetoes its own rewrite.

A mark used to outlive the bytes it described. A failed display write
left the page showing the file's own caption while the verdict still
claimed its state was drawn; a metadata edit dropped the mark while
the page kept drawing the state, so the badge landed on top of it. The
write fallback now drops the marks and logs the loss, and metadata
carries them over.

Tests: a self-referential appearance tree, which never finished before
the budget, two widgets sharing one appearance, a metadata edit that
keeps its mark, a save that goes through the writer instead of
short-circuiting on the opened file, and the snapshot bar's Close
button pressed for real.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* Cite the new regressions in parity, restore main's installer note

The appearance entry now cites the bounded walk and the save through
the writer, and says what a tree that cannot be read to the end does.
The installer entry carried main's older text, which still claims
signed installers are planned; main's newer note is taken verbatim.

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>

* M9: preserve rounded decoration beside raster status glyphs

* M9: place appearance progress beside signature history

* M9: retain appearances with ambiguous curved layers

* M9: keep signature verdicts in viewer overlays

Defer generic appearance rewriting: caption text and a unique drawing do not establish an icon role. Preserve original artwork for saves, image and text exports, and both print modes while retaining snapshot reuse and trust refresh. Cover chamfered borders and mixed signer/caption streams through signed Session round trips.

---------

Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
Co-authored-by: skylar taylor-barrick <hi@skylar.cc>

parity/acrobat-features.toml

@@ -4404,8 +4404,8 @@ milestone = "M2"
 status = "shipped"
 commands = []
 tools = []
-evidence = ["crates/render/src/raster.rs::widget_appearance_states"]
-notes = ""
+evidence = ["crates/render/src/raster.rs::widget_appearance_states", "crates/engine/src/tests.rs::validated_signatures_without_layers_keep_their_appearance", "crates/engine/src/tests.rs::real_layered_signatures_keep_their_original_appearance", "crates/engine/src/tests.rs::real_layered_signatures_round_trip_behind_a_user_password", "crates/engine/src/tests.rs::a_metadata_edit_keeps_the_original_signature_appearance", "crates/engine/src/tests.rs::saving_after_an_edit_keeps_the_baked_appearance", "crates/engine/src/tests.rs::chamfered_signature_borders_survive_trust_exports_printing_and_save", "crates/engine/src/tests.rs::mixed_signature_caption_details_survive_trust_exports_printing_and_save"]
+notes = "widgets retain their original artwork. Signature validation is a separate viewer page overlay; it is never written into document streams or included in image/text exports, vector printing or Print as Image. Saves retain signed appearance bytes. Generic in-place appearance rewriting is deferred: no supported producer template is positively identified, and caption text plus drawing uniqueness does not establish an icon role. Baked Not Verified captions remain unchanged; issue #79 is not fully resolved."
 
 [[feature]]
 id = "form.fill-text"
@@ -6224,8 +6224,8 @@ milestone = "M9"
 status = "shipped"
 commands = ["sign.panel"]
 tools = []
-evidence = ["crates/ui-egui/tests/signing.rs::drawing_a_signature_creating_an_id_signing_and_trusting", "crates/ui-egui/tests/signing.rs::certifying_without_a_visible_signature"]
-notes = "signed/valid, problems, invalid and certified bars"
+evidence = ["crates/ui-egui/tests/signing.rs::drawing_a_signature_creating_an_id_signing_and_trusting", "crates/ui-egui/tests/signing.rs::certifying_without_a_visible_signature", "crates/ui-egui/src/canvas.rs::signature_badges_keep_signed_visible_widgets_on_the_page"]
+notes = "signed/valid, problems, invalid and certified bars; visible signed widgets also carry a separate viewer validation overlay. Trust and explicit validation invalidate view caches without editing document artwork; baked appearance captions remain unchanged."
 
 [[feature]]
 id = "sign.signature-properties"
@@ -6333,7 +6333,7 @@ status = "shipped"
 commands = ["sign.panel"]
 tools = []
 evidence = ["crates/ui-egui/tests/signing.rs::drawing_a_signature_creating_an_id_signing_and_trusting"]
-notes = ""
+notes = "repeats reuse the tab, whose name keeps the (signed version) suffix instead of the document title; the tab carries a notice bar naming the revision, with a Close that asks about saving first. Still missing: the snapshot is a full editable document rather than a read-only view, and there is no side-by-side compare (sign.compare-signed-version)"
 
 [[feature]]
 id = "sign.compare-signed-version"