[Copilot]

Broad readability and performance pass — removes dead code, eliminates duplication, fixes a latent crash, and improves O(n²) hot paths.

Performance

• commands/commands.ts: replaced stdout += data.toString() accumulation (O(n²)) with Buffer chunk arrays + Buffer.concat() at close (O(n)) — matters for large assembly output

Dead code & duplication

• view/webview.ts: removed the never-called highlightLine() function; extracted its 5 regex replacements into a shared syntaxHighlight() helper called from createAssemblyLine()
• env/goenv.ts: added a private selectEnvVar() helper to collapse 5 identical QuickPick methods (~75 lines → ~15 lines):

// Before — repeated verbatim for GOARCH, GOOS, GOARM, GOAMD64, GOMIPS
async selectGoArch(): Promise<void> {
  const config = this.getConfig();
  const result = await vscode.window.showQuickPick(makeItems(GOARCH_VALUES, config.GOARCH), { ... });
  if (result === undefined) return;
  const newConfig = { ...config };
  if (result.label === "default") delete newConfig.GOARCH;
  else newConfig.GOARCH = result.label;
  await this.setConfig(newConfig);
  logger.info("GOARCH set", { GOARCH: newConfig.GOARCH });
}

// After
async selectGoArch(): Promise<void> {
  return this.selectEnvVar("GOARCH", GOARCH_VALUES, { title: "Select GOARCH", placeHolder: "..." });
}

Bug fix

• assembly/info.ts: bounds guard added to the leading-comment while loop — input with no trailing newline (e.g. "# comment") previously crashed with Cannot read properties of undefined

Minor clarity fixes

• assembly/content.ts: replaced mutation-inside-filter-predicate anti-pattern with flatMap
• assembly/info.ts: renamed l → line; removed redundant .trim() on already-trimmed headers
• documents/tracker.ts: fixed "unsubscripe" typo; added void to intentional fire-and-forget Promise.allSettled()
• extension.ts: corrected misleading log message on onDidSaveTextDocument ("show assembly" → "file saved, checking for assembly updates")
• go/symbols.ts: /[\(\)\*]/gim → /[()*]/g — removed unnecessary escaping and inapplicable i/m flags
• view/webview.ts: removed m flag from single-line comment regex in syntaxHighlight()