Document expected memory footprint

~200 MB macOS / ~300 MB Windows is normal for a Bun + system-WebView app;
record the process breakdown, why Windows (WebView2/Chromium) is higher,
that it's not a bug, and the only real growth levers, so it isn't
re-investigated.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/platform-notes.md

@@ -26,6 +26,29 @@ Every platform seam carries a `PORTABILITY:` comment at the branch site.
 Remote (SFTP) paths are ALWAYS POSIX regardless of host or server OS
 (`path.posix` throughout `fs/sftp.ts`).
 
+## Memory footprint (expected, not a bug)
+
+Investigated 2026-07 — packaged build. Roughly **~200 MB macOS / ~300 MB
+Windows**, which is normal for a Bun + system-WebView app (30 MB is native /
+no-web-engine territory; Tauri-class apps run ~80–200 MB, Electron 150–400 MB).
+Not reducible to tens of MB without dropping the web UI.
+
+- macOS splits across several "miniSCP" processes: the **Bun main** (~120 MB:
+  backend + the bundled electrobun runtime + live SSH sessions — the largest and
+  least reducible piece), the **`views://app`** WKWebView content process (~60 MB,
+  the Angular UI), and the standard WebKit **Networking** / **Graphics and
+  Media** helpers. All are one app; WebKit just names them per-role.
+- Windows is higher because **WebView2 is Chromium** (multi-process: browser +
+  GPU + renderer + utility + crashpad), vs macOS's lighter WKWebKit.
+- Measure against a **packaged** build — `bun run dev` inflates the WebContent
+  heap (ng-serve, unminified, sourcemaps, live-reload) and is not representative.
+- Verified non-issues: transfers stream (no whole-file buffering), icons
+  tree-shaken to ~33 glyphs, zoneless Angular, 364 KB prod bundle.
+- Only real growth levers if this ever matters: the file list is **not
+  virtualized** (a directory with tens of thousands of entries retains a DOM row
+  each), and each open tab keeps both panels' full `entries` arrays; terminal
+  transfers are retained until cleared. None affect normal use.
+
 ## Windows known issues (upstream electrobun, documented not fixed)
 
 - **HiDPI blur** — WebView2 renders at 1x on scaled displays