fix: improve snapshot flags docs completeness for LLM judge

Adds $B placeholder explanation, explicit syntax line, and detailed
flag behavior (-d depth values, -s CSS selector syntax, -D unified
diff format and baseline persistence, -a screenshot vs text output
relationship). Fixes snapshot flags reference LLM eval scoring
completeness < 4.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

SKILL.md

@@ -706,6 +706,9 @@ $B css ".button" "background-color"
 ## Snapshot System
 
 The snapshot is your primary tool for understanding and interacting with pages.
+`$B` is the browse binary (resolved from `$_ROOT/.claude/skills/gstack/browse/dist/browse` or `~/.claude/skills/gstack/browse/dist/browse`).
+
+**Syntax:** `$B snapshot [flags]`
 
 ```
 -i        --interactive           Interactive elements only (buttons, links, inputs) with @e refs. Also auto-enables cursor-interactive scan (-C) to capture dropdowns and popovers.
@@ -721,6 +724,12 @@ The snapshot is your primary tool for understanding and interacting with pages.
 All flags can be combined freely. `-o` only applies when `-a` is also used.
 Example: `$B snapshot -i -a -C -o /tmp/annotated.png`
 
+**Flag details:**
+- `-d <N>`: depth 0 = root element only, 1 = root + direct children, etc. Default: unlimited. Works with all other flags including `-i`.
+- `-s <sel>`: any valid CSS selector (`#main`, `.content`, `nav > ul`, `[data-testid="hero"]`). Scopes the tree to that subtree.
+- `-D`: outputs a unified diff (lines prefixed with `+`/`-`/` `) comparing the current snapshot against the previous one. First call stores the baseline and returns the full tree. Baseline persists across navigations until the next `-D` call resets it.
+- `-a`: saves an annotated screenshot (PNG) with red overlay boxes and @ref labels drawn on each interactive element. The screenshot is a separate output from the text tree — both are produced when `-a` is used.
+
 **Ref numbering:** @e refs are assigned sequentially (@e1, @e2, ...) in tree order.
 @c refs from `-C` are numbered separately (@c1, @c2, ...).
 

browse/SKILL.md

@@ -574,6 +574,9 @@ After `resume`, you get a fresh snapshot of wherever the user left off.
 ## Snapshot Flags
 
 The snapshot is your primary tool for understanding and interacting with pages.
+`$B` is the browse binary (resolved from `$_ROOT/.claude/skills/gstack/browse/dist/browse` or `~/.claude/skills/gstack/browse/dist/browse`).
+
+**Syntax:** `$B snapshot [flags]`
 
 ```
 -i        --interactive           Interactive elements only (buttons, links, inputs) with @e refs. Also auto-enables cursor-interactive scan (-C) to capture dropdowns and popovers.
@@ -589,6 +592,12 @@ The snapshot is your primary tool for understanding and interacting with pages.
 All flags can be combined freely. `-o` only applies when `-a` is also used.
 Example: `$B snapshot -i -a -C -o /tmp/annotated.png`
 
+**Flag details:**
+- `-d <N>`: depth 0 = root element only, 1 = root + direct children, etc. Default: unlimited. Works with all other flags including `-i`.
+- `-s <sel>`: any valid CSS selector (`#main`, `.content`, `nav > ul`, `[data-testid="hero"]`). Scopes the tree to that subtree.
+- `-D`: outputs a unified diff (lines prefixed with `+`/`-`/` `) comparing the current snapshot against the previous one. First call stores the baseline and returns the full tree. Baseline persists across navigations until the next `-D` call resets it.
+- `-a`: saves an annotated screenshot (PNG) with red overlay boxes and @ref labels drawn on each interactive element. The screenshot is a separate output from the text tree — both are produced when `-a` is used.
+
 **Ref numbering:** @e refs are assigned sequentially (@e1, @e2, ...) in tree order.
 @c refs from `-C` are numbered separately (@c1, @c2, ...).
 

scripts/resolvers/browse.ts

@@ -54,6 +54,9 @@ export function generateCommandReference(_ctx: TemplateContext): string {
 export function generateSnapshotFlags(_ctx: TemplateContext): string {
   const lines: string[] = [
     'The snapshot is your primary tool for understanding and interacting with pages.',
+    '`$B` is the browse binary (resolved from `$_ROOT/.claude/skills/gstack/browse/dist/browse` or `~/.claude/skills/gstack/browse/dist/browse`).',
+    '',
+    '**Syntax:** `$B snapshot [flags]`',
     '',
     '```',
   ];
@@ -68,6 +71,12 @@ export function generateSnapshotFlags(_ctx: TemplateContext): string {
   lines.push('All flags can be combined freely. `-o` only applies when `-a` is also used.');
   lines.push('Example: `$B snapshot -i -a -C -o /tmp/annotated.png`');
   lines.push('');
+  lines.push('**Flag details:**');
+  lines.push('- `-d <N>`: depth 0 = root element only, 1 = root + direct children, etc. Default: unlimited. Works with all other flags including `-i`.');
+  lines.push('- `-s <sel>`: any valid CSS selector (`#main`, `.content`, `nav > ul`, `[data-testid="hero"]`). Scopes the tree to that subtree.');
+  lines.push('- `-D`: outputs a unified diff (lines prefixed with `+`/`-`/` `) comparing the current snapshot against the previous one. First call stores the baseline and returns the full tree. Baseline persists across navigations until the next `-D` call resets it.');
+  lines.push('- `-a`: saves an annotated screenshot (PNG) with red overlay boxes and @ref labels drawn on each interactive element. The screenshot is a separate output from the text tree — both are produced when `-a` is used.');
+  lines.push('');
   lines.push('**Ref numbering:** @e refs are assigned sequentially (@e1, @e2, ...) in tree order.');
   lines.push('@c refs from `-C` are numbered separately (@c1, @c2, ...).');
   lines.push('');