merge: origin/main v1.1.0.0 into garrytan/fix-checkpoints

Main shipped browse Puppeteer parity (v1.1.0.0 — goto file://,
load-html, screenshot --selector, viewport --scale). Resolved conflicts:

- VERSION / package.json: bumped 1.0.1.0 → 1.1.1.0 (main is 1.1.0.0,
  this branch lands next).
- CHANGELOG: moved the /context-save + /context-restore entry to the
  top as v1.1.1.0, above main's v1.1.0.0.
- Migration: renamed gstack-upgrade/migrations/v1.0.1.0.sh →
  v1.1.1.0.sh (matches new version). Test path updated. Migration
  version string inside the script also updated.

No overlap between browse changes and context-save/context-restore code.
SKILL.md files regenerated via bun run gen:skill-docs --host all per
CLAUDE.md's "never resolve generated files by accepting either side"
rule. Golden fixtures (claude/codex/factory ship) regenerated.

bun test: 0 failures. Migration ownership guard: 7/7 pass (~85ms).

SKILL.md

@@ -798,7 +798,8 @@ Refs are invalidated on navigation — run `snapshot` again after `goto`.
 |---------|-------------|
 | `back` | History back |
 | `forward` | History forward |
-| `goto <url>` | Navigate to URL |
+| `goto <url>` | Navigate to URL (http://, https://, or file:// scoped to cwd/TEMP_DIR) |
+| `load-html <file> [--wait-until load|domcontentloaded|networkidle]` | Load a local HTML file via setContent (no HTTP server needed). For self-contained HTML (inline CSS/JS, data URIs). For HTML on disk, goto file://... is often cleaner. |
 | `reload` | Reload page |
 | `url` | Print current URL |
 
@@ -849,7 +850,7 @@ Refs are invalidated on navigation — run `snapshot` again after `goto`.
 | `type <text>` | Type into focused element |
 | `upload <sel> <file> [file2...]` | Upload file(s) |
 | `useragent <string>` | Set user agent |
-| `viewport <WxH>` | Set viewport size |
+| `viewport [<WxH>] [--scale <n>]` | Set viewport size and optional deviceScaleFactor (1-3, for retina screenshots). --scale requires a context rebuild. |
 | `wait <sel|--networkidle|--load>` | Wait for element, network idle, or page load (timeout: 15s) |
 
 ### Inspection
@@ -876,7 +877,7 @@ Refs are invalidated on navigation — run `snapshot` again after `goto`.
 | `pdf [path]` | Save as PDF |
 | `prettyscreenshot [--scroll-to sel|text] [--cleanup] [--hide sel...] [--width px] [path]` | Clean screenshot with optional cleanup, scroll positioning, and element hiding |
 | `responsive [prefix]` | Screenshots at mobile (375x812), tablet (768x1024), desktop (1280x720). Saves as {prefix}-mobile.png etc. |
-| `screenshot [--viewport] [--clip x,y,w,h] [selector|@ref] [path]` | Save screenshot (supports element crop via CSS/@ref, --clip region, --viewport) |
+| `screenshot [--selector <css>] [--viewport] [--clip x,y,w,h] [--base64] [selector|@ref] [path]` | Save screenshot. --selector targets a specific element (explicit flag form). Positional selectors starting with ./#/@/[ still work. |
 
 ### Snapshot
 | Command | Description |