refactor(shake): removed shake-summary mode and local-model compressor

- Dropped `summarizeShakeRegions`, the shake-summary prompt, and related types.
- Removed `shake-summary` compaction strategy and `providers.shakeSummaryModel` setting.
- Migrated existing `shake-summary` configs to plain `shake` on load.
- Simplified `/shake` to `elide` and `images` modes only.

packages/coding-agent/src/modes/controllers/command-controller.ts

@@ -1124,48 +1124,16 @@ export class CommandController {
 	}
 
 	/**
-	 * TUI handler for `/shake`. `elide`/`images` are instant structural drops;
-	 * `summary` runs the local on-device compressor behind a cancelable loader
-	 * (Esc aborts via `abortCompaction`). Rebuilds the chat and reports counts.
+	 * TUI handler for `/shake`. `elide` drops heavy structural content and
+	 * `images` strips image blocks. Rebuilds the chat and reports counts.
 	 */
 	async handleShakeCommand(mode: ShakeMode): Promise<void> {
 		let result: ShakeResult;
-		if (mode === "summary") {
-			if (this.ctx.loadingAnimation) {
-				this.ctx.loadingAnimation.stop();
-				this.ctx.loadingAnimation = undefined;
-			}
-			this.ctx.statusContainer.clear();
-			const originalOnEscape = this.ctx.editor.onEscape;
-			this.ctx.editor.onEscape = () => {
-				this.ctx.session.abortCompaction();
-			};
-			const loader = new Loader(
-				this.ctx.ui,
-				spinner => theme.fg("accent", spinner),
-				text => theme.fg("muted", text),
-				"Shaking context (summary)… (esc to cancel)",
-				getSymbolTheme().spinnerFrames,
-			);
-			this.ctx.statusContainer.addChild(loader);
-			this.ctx.ui.requestRender();
-			try {
-				result = await this.ctx.session.shake("summary");
-			} catch (error) {
-				this.ctx.showError(`Shake failed: ${error instanceof Error ? error.message : String(error)}`);
-				return;
-			} finally {
-				loader.stop();
-				this.ctx.statusContainer.clear();
-				this.ctx.editor.onEscape = originalOnEscape;
-			}
-		} else {
-			try {
-				result = await this.ctx.session.shake(mode);
-			} catch (error) {
-				this.ctx.showError(`Shake failed: ${error instanceof Error ? error.message : String(error)}`);
-				return;
-			}
+		try {
+			result = await this.ctx.session.shake(mode);
+		} catch (error) {
+			this.ctx.showError(`Shake failed: ${error instanceof Error ? error.message : String(error)}`);
+			return;
 		}
 
 		const dropped = result.toolResultsDropped + result.blocksDropped + (result.imagesDropped ?? 0);