feat(999.70-02): document Restore Defaults scope — help page + button tooltip (TUT-02, #523)

Restore Defaults resets only the currently-open Preferences page and intentionally
does NOT reset font/language/style (style_box_/languageComboBox_ are unregistered
from the reset path; font is held separately). Document this on two surfaces:
- new in-app help page data/BALLView/help/preferences/01-restore-defaults.md
- null-guarded tr() tooltip on the QDialogButtonBox::RestoreDefaults button
No reset behavior changed. VIEW builds clean. TUT-01 PDF/screenshots remain Wave-2 (human).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: okohlbacher

.planning/REQUIREMENTS.md

@@ -282,7 +282,7 @@ collision with prior PKG/DOCS/FEAT IDs.
 
 ### Documentation (Phase 999.56)
 - [ ] **TUT-01**: The PDF tutorial content / screenshots / URLs / build-flow are refreshed to the v1.7.x stack (#560).
-- [ ] **TUT-02**: The "Restore Defaults" scope (does not reset font / language / style) is documented (#523).
+- [x] **TUT-02**: The "Restore Defaults" scope (does not reset font / language / style) is documented (#523).
 
 ### Inspector cosmetic (v1.7.5 carry-in)
 - [ ] **INSPCLIP-01**: Right-edge Inspector controls (per-section reset glyphs, value spinners, unit labels) are not clipped when an Inspector tab scrolls (the v1.7.4 known issue).

.planning/phases/999.70-pdf-tutorial-docs/999.70-02-SUMMARY.md

@@ -0,0 +1,39 @@
+# 999.70-02 Summary — Restore Defaults scope docs (TUT-02 / #523)
+
+**Status:** complete (autonomous). Executed inline by the orchestrator after the
+Wave-1 executor stalled on the stream watchdog (TUT-01 commits recovered + merged;
+TUT-02 finished here).
+
+## Delivered on two surfaces
+
+1. **In-app help page** — `data/BALLView/help/preferences/01-restore-defaults.md`
+   (new `preferences/` help section; markdown + YAML frontmatter matching the
+   existing `help/tutorial/` pages). States explicitly that Restore Defaults
+   resets only the *currently open* page's registered values and does **not**
+   reset **font**, **language**, or **style**, and points users to
+   Preferences → General to change those.
+
+2. **Button tooltip** — `source/VIEW/DIALOGS/preferences.C`, in the
+   `Preferences(QWidget*, const char*)` constructor (after `setupUi`):
+   ```
+   "Resets this page's settings to their defaults. Font, language, and
+    interface style are not changed."
+   ```
+   Retrieved via `buttonBox->button(QDialogButtonBox::RestoreDefaults)`,
+   null-guarded, wrapped in `tr()` for i18n. No reset behavior changed.
+
+## Accuracy basis
+Wording derived directly from the confirmed code path: `setDefaultValues()` →
+`restoreDefaultValues()` on the selected page only; `mainControlPreferences.C`
+deliberately `unregisterObject_(style_box_)` / `unregisterObject_(languageComboBox_)`,
+and the font is held in a separate `font_` member — all outside the registered-object
+reset path. Intentional design (#523, confirmed by A. Hildebrandt), documented not changed.
+
+## Verification
+- Both plan verify gates PASS (help page names font/language/style + "not changed";
+  tooltip present on the RestoreDefaults button mentioning the three).
+- `cmake --build build/ci-macos --target VIEW` — `preferences.C` compiled clean,
+  libVIEW linked.
+
+## Not done here (Wave 2 / human — plan 999.70-03)
+TUT-01's PDF render + `tut1_screenshot` recapture remain a human checkpoint.

data/BALLView/help/preferences/01-restore-defaults.md

@@ -0,0 +1,43 @@
+---
+title: Restore Defaults
+order: 1
+prev: null
+next: null
+prereq: none
+expected-runtime: 1 minute
+---
+
+# Restore Defaults
+
+The **Restore Defaults** button at the bottom of the Preferences
+dialog resets the settings on the **currently open Preferences
+page** back to their built-in default values. It acts on the page
+you have selected in the list on the left — not on every page at
+once. To restore another page, open it first, then click Restore
+Defaults again.
+
+## What is *not* reset
+
+Restore Defaults deliberately leaves three General-tab settings
+unchanged:
+
+- your chosen application **font**,
+- the interface **language**, and
+- the widget **style**.
+
+These three are intentionally preserved so that an accidental
+click cannot, for example, switch your interface back to English
+or to a different platform style in the middle of a session. This
+is by design, not a bug — Restore Defaults will never touch them.
+
+## How to change font, language, or style
+
+Set them directly in **Preferences → General**:
+
+- **Font** — pick a new application font.
+- **Language** — choose the interface language (a restart may be
+  required for the change to take full effect).
+- **Style** — select the widget style.
+
+Changing them here applies immediately (or after the noted
+restart); they are simply outside the scope of Restore Defaults.

source/VIEW/DIALOGS/preferences.C

@@ -30,7 +30,20 @@ namespace BALL
 		{
 			setupUi(this);
 			setObjectName(name);
-			
+
+			// TUT-02 (#523): document the Restore Defaults scope at the point of
+			// confusion. The button resets only the currently-open page's
+			// registered values; font/language/style are intentionally outside
+			// the reset path (mainControlPreferences unregisters style_box_ and
+			// languageComboBox_, and the font is held separately), so users who
+			// expect those to revert are surprised. Spell out the scope here.
+			// The button may be absent on some platform layouts — null-guard it.
+			if (QPushButton* restore_button = buttonBox->button(QDialogButtonBox::RestoreDefaults))
+			{
+				restore_button->setToolTip(tr("Resets this page's settings to their defaults. "
+				                              "Font, language, and interface style are not changed."));
+			}
+
 			// signals and slots connections
 			connect( entries_listview, SIGNAL(itemSelectionChanged()), this, SLOT(entrySelected()));
 			//for some reason the ok_button and the apply button is connected in VIEW/KERNEL/mainControl.C