port: bump the formats pin to formats-pin-2026-09-01 for the blend accessors

What I wanted from the new state: `ui_layout::sprite_blend_additive` and its
three siblings, which expose `T8aD +0x04` bit 0x02 -- the decoded blend mode.

Until this tag, `Element` surfaced `kind` (+40), `parent`, pivot, keyframes and
`focus_link`, all from the RATC record, and nothing reached the sprite's own
header. That is why the port has been carrying an authored additive map keyed by
SCREEN NAME, transcribed from the Decoder's per-draw RB_BLENDCONTROL0 log, which
cannot answer for a screen nobody drove the game to -- the Japanese menus being
the case that raised it.

Both spellings are needed, not one: `sprite_blend_additive` takes an &Element,
and `blend_additive_by_name` takes a sprite name, because a button's focused
variant is reached through focus_link and `ptbtn00f.t32` is in build.sprites
while no element carries it as `sprite`. That is exactly the sharp case in my
own map -- press_start's only additive entry IS ptbtn00f.

Pin bumped as its own commit, per PORT-MISSION §2. Nothing else in this commit;
the exporter does not read the new accessors yet.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018AHUQvXGyNcKonSEWsgWcX

crates/sylpheed-export/Cargo.toml

@@ -81,7 +81,7 @@ license.workspace = true
 # geometry -- does NOT reach this port from here: `sylpheed-cli` builds from the
 # WORKSPACE crate, so the reference renderer stays unrotated until the tag lands
 # on `main`. This bump is for the parser, not for the renderer.
-sylpheed-formats = { git = "https://git.mc02.dev/fabi/Sylpheed.git", tag = "formats-pin-2026-08-30b" }
+sylpheed-formats = { git = "https://git.mc02.dev/fabi/Sylpheed.git", tag = "formats-pin-2026-09-01" }
 
 serde      = { version = "1", features = ["derive"] }
 serde_json = "1"