feat: hatch PDF draw order (#1345), numeric CAS (#1348), web automation (#1349), DATALINK table, System theme; honest decode accounting

Upstream issues, fixed:

#1345 — hatches plotted at draw_depth 0.0: the plot path cloned models
from the hatch cache, which bakes the depth at seed time; the canvas
re-reads the live depth map every frame, which is why the editor was
right and every export (PDF and native printing — both route through
the exporter) was wrong, with hatch-vs-hatch ties broken by HashMap
order. The plot path now re-reads the depth map per entity, and the
exporter's tie-break ranks follow the editor's own pass order
(hatch < image < wire fill < wire < text < wipeout) instead of pinning
hatches between fills and wires. Pinned by content-stream operator-
order tests (back/front hatches, overlapping hatches, interleaved
wire-between-hatches) and a scene test that fails pre-fix.

#1348 — set_properties' optimistic-concurrency compare now matches
numbers by value (10.0 == 10) through json_values_match, compatible
with the shape of upstream PR #1350; nested objects/arrays recurse.

#1349 — web automation contract: control protocol 2 (v1 clients still
accepted) adds {op:'open', name, data_base64} routed through the
guarded open queue; window.ocsControl.ready/request promise wrapper
with an ocs-ready event (web/ocs-control.js); the startup donation
prompt is suppressed once a control request is seen (opt-in pre-boot
via localStorage); docs/automation documents the whole web contract.

Also: DATALINK CSV-to-table works on web (picker + bytes through the
session registry — was std::fs, silently dead); COLORSCHEME accepts
System (prefers-color-scheme on web, AppsUseLightTheme on Windows).

Decode accounting, made honest per the fix-of-fix review: into_rgba8
allocates the RGBA destination while the native buffer is alive for
every non-Rgba8 layout (L8 5, La8 6, Rgb8 7, L16 6, La16 8 B/px
peaks — the formula now says so), GIF bills the screen+frame
coexistence at 8 B/px, and TIFF drops the 3x multipliers both ways —
tiff 0.11 splits the given budget between frame and scratch (a total
ceiling), so the old double-billing refused honest 16-bit GeoTIFFs
~2.25x early while admitting hostile chunk transients at 3x. The
image-refusal-unknown-size locale key moves to the group the catalog
always claimed (file).

src/app/update/mod.rs

@@ -2453,6 +2453,12 @@ impl OpenCADStudio {
             #[cfg(target_arch = "wasm32")]
             Message::ScriptFilePicked(None) => Task::none(),
 
+            // Web DATALINK: the picked .csv's bytes arrived — register them
+            // as the link's in-session source, then run the same table-insert
+            // path the native typed-path command feeds.
+            #[cfg(target_arch = "wasm32")]
+            Message::DataLinkCsvPicked(picked) => self.on_datalink_csv_picked(picked),
+
             // Web CENTERLTYPEFILE: the picked .lin/.dnl file's text arrived —
             // load its linetypes, then record the setting under the file's
             // name (the native command reads the typed path inside