feat: add missing Annotate tab commands and icons

New dimension commands: QDIM, DIMEDIT, DIMTEDIT, DIMBREAK, DIMSPACE,
DIMJOGLINE with full command workflows and SVG icons.

New multileader commands: MLEADERADD, MLEADERREMOVE, MLEADERALIGN,
MLEADERCOLLECT with entity injection pattern for in-place editing.

Updated annotate ribbon: all tools exposed across Text, Dimensions,
Leaders, Tables, Markup, and Annotation Scaling groups. Added STYLE,
FIND, DIMSTYLE shortcut buttons.

Added `inject_picked_entity` to the CadCommand trait for commands that
need a cloned copy of the picked entity to modify (DIMTEDIT, MLEADERADD,
MLEADERREMOVE). Sentinel-based dispatch in cmd_result.rs handles
DIMBREAK, DIMSPACE, DIMJOGLINE, MLEADERALIGN, and MLEADERCOLLECT.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/annotate/dimedit.rs

@@ -0,0 +1,75 @@
+// DIMEDIT command — edit dimension text or reset it to the measured value.
+//
+// Workflow:
+//   1. Pick a dimension entity
+//   2. Enter new text (blank = reset to auto-measured value, "<>" = measured value placeholder)
+
+use acadrust::Handle;
+use glam::Vec3;
+
+use crate::command::{CadCommand, CmdResult};
+use crate::modules::{IconKind, ModuleEvent, ToolDef};
+
+pub const ICON: IconKind = IconKind::Svg(include_bytes!("../../../assets/icons/dim_edit.svg"));
+
+pub fn tool() -> ToolDef {
+    ToolDef {
+        id: "DIMEDIT",
+        label: "Dim Edit",
+        icon: ICON,
+        event: ModuleEvent::Command("DIMEDIT".to_string()),
+    }
+}
+
+enum Step {
+    PickDim,
+    EnterText { handle: Handle },
+}
+
+pub struct DimEditCommand {
+    step: Step,
+}
+
+impl DimEditCommand {
+    pub fn new() -> Self {
+        Self { step: Step::PickDim }
+    }
+}
+
+impl CadCommand for DimEditCommand {
+    fn name(&self) -> &'static str { "DIMEDIT" }
+
+    fn prompt(&self) -> String {
+        match &self.step {
+            Step::PickDim => "DIMEDIT  Select dimension:".into(),
+            Step::EnterText { .. } => "DIMEDIT  Enter text override (blank = reset to measured):".into(),
+        }
+    }
+
+    fn needs_entity_pick(&self) -> bool {
+        matches!(self.step, Step::PickDim)
+    }
+
+    fn on_entity_pick(&mut self, handle: Handle, _pt: Vec3) -> CmdResult {
+        if handle.is_null() { return CmdResult::NeedPoint; }
+        self.step = Step::EnterText { handle };
+        CmdResult::NeedPoint
+    }
+
+    fn wants_text_input(&self) -> bool {
+        matches!(self.step, Step::EnterText { .. })
+    }
+
+    fn on_text_input(&mut self, text: &str) -> Option<CmdResult> {
+        let handle = match &self.step {
+            Step::EnterText { handle } => *handle,
+            _ => return None,
+        };
+        // Empty = reset to auto-measured, "<>" = keep measured, else override
+        let new_text = text.trim().to_string();
+        Some(CmdResult::DdeditEntity { handle, new_text })
+    }
+
+    fn on_point(&mut self, _pt: Vec3) -> CmdResult { CmdResult::NeedPoint }
+    fn on_enter(&mut self) -> CmdResult { CmdResult::Cancel }
+}