Name the frame's category for the decision, not the maths

`Attribute::Geometry` becomes `Attribute::Compose`, and `film_sim` moves
from `[tone, colour]` to `[effect]`.

Two categories were doing the wrong job. "Geometry" describes what crop,
straighten and the quarter turns do to coordinates — but it describes lens
distortion correction exactly as well, and that is not a compositional
choice at all. Naming the attribute for the photographer's decision is what
separates it from `Optics`: one is what the lens did, the other is what
they chose. The maths the two have in common is not the thing worth
filing them under.

A film stock declared both `tone` and `colour`, so "Kodachrome" appeared in
the Light group beside exposure and again in Colour beside white balance —
two places, neither of which is where anyone looks for it. It is neither:
`Effect` is defined in this same file as "applied rather than corrected — a
look, not a fix", which is what a stock is. That it moves tone and colour
is true of every look, and is not what the attribute is for.

`from_name` still accepts "geometry" on the way in. That string is
persisted in `develop.copy_attributes`, and an entry it fails to parse is
not an error — `presets::scope_for` logs it and drops it — so without the
alias an existing settings file would have quietly narrowed what a paste
carries. `name` writes the current spelling, so the file migrates itself
the first time it is saved.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

core/dr-pipeline/src/descriptor.rs

@@ -580,8 +580,15 @@ pub enum Attribute {
     /// Corrections for the lens that took the photograph: distortion,
     /// chromatic aberration, vignetting.
     Optics,
-    /// The shape of the frame: crop, straighten, rotation, flips.
-    Geometry,
+    /// How the frame is composed: crop, straighten, rotation, flips.
+    ///
+    /// Named for the decision rather than for the maths. The lens corrections
+    /// are geometry too — distortion moves pixels exactly as a straighten
+    /// does — and lumping the two together would file a correction the
+    /// photographer never asked for beside a choice that is the whole reason
+    /// they opened the photograph. [`Self::Optics`] is what the lens did;
+    /// this is what they decided.
+    Compose,
     /// Applied rather than corrected — a look, not a fix.
     Effect,
 }
@@ -598,7 +605,7 @@ impl Attribute {
         Attribute::Colour,
         Attribute::Detail,
         Attribute::Optics,
-        Attribute::Geometry,
+        Attribute::Compose,
         Attribute::Effect,
     ];
 
@@ -613,7 +620,7 @@ impl Attribute {
             Self::Colour => "attr.colour",
             Self::Detail => "attr.detail",
             Self::Optics => "attr.optics",
-            Self::Geometry => "attr.geometry",
+            Self::Compose => "attr.compose",
             Self::Effect => "attr.effect",
         })
     }
@@ -630,7 +637,7 @@ impl Attribute {
             Self::Colour => "colour",
             Self::Detail => "detail",
             Self::Optics => "optics",
-            Self::Geometry => "geometry",
+            Self::Compose => "compose",
             Self::Effect => "effect",
         }
     }
@@ -642,7 +649,15 @@ impl Attribute {
             "colour" => Self::Colour,
             "detail" => Self::Detail,
             "optics" => Self::Optics,
-            "geometry" => Self::Geometry,
+            "compose" => Self::Compose,
+            // The name this attribute was persisted under before it was
+            // called Compose. Settings written by an older build carry it in
+            // `develop.copy_attributes`, and `from_name` returning `None`
+            // there does not fail loudly — `presets::scope_for` logs and drops
+            // the entry, silently narrowing what a paste carries. Accepted on
+            // the way in only; `name` writes the current spelling, so a
+            // settings file rewrites itself the first time it is saved.
+            "geometry" => Self::Compose,
             "effect" => Self::Effect,
             _ => return None,
         })