feat: add section heading icons to PDF templates (#3127)

* feat: add section heading icons to PDF templates

Add customizable Phosphor icons before section titles in PDF output.
Users can toggle visibility globally via a new "Hide section heading icons"
switch (independent of item-level icons) and customize individual section
icons through the builder sidebar icon picker.

- Add `icon` field to `baseSectionSchema` and `summarySchema`
- Add `hideSectionIcons` to `pageSchema` (defaults to true for backward compat)
- Implement `SectionHeadingIcon` component with heading font-size scaling
- Support "none" sentinel for per-section icon hiding
- Fallback to sensible defaults (briefcase, graduation-cap, etc.) for legacy data
- Add icon picker to builder sidebar sections and custom section dialogs

Closes #2632

* test: add unit tests for section heading icons

- Add tests for getResumeSectionIcon() covering built-in sections,
  summary, custom sections, "none" sentinel, and default fallbacks
- Add schema tests for baseSectionSchema icon field, summarySchema icon,
  and pageSchema hideSectionIcons default behavior

* refactor: minor updates to icon display

* Update apps/web/locales/es-ES.po

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Co-authored-by: Amruth Pillai <im.amruth@gmail.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

apps/web/locales/ru-RU.po

@@ -8,7 +8,7 @@ msgstr ""
 "Language: ru\n"
 "Project-Id-Version: reactive-resume\n"
 "Report-Msgid-Bugs-To: \n"
-"PO-Revision-Date: 2026-05-27 21:53\n"
+"PO-Revision-Date: 2026-06-01 11:26\n"
 "Last-Translator: \n"
 "Language-Team: Russian\n"
 "Plural-Forms: nplurals=4; plural=((n%10==1 && n%100!=11) ? 0 : ((n%10 >= 2 && n%10 <=4 && (n%100 < 12 || n%100 > 14)) ? 1 : ((n%10 == 0 || (n%10 >= 5 && n%10 <=9)) || (n%100 >= 11 && n%100 <= 14)) ? 2 : 3));\n"
@@ -1745,8 +1745,8 @@ msgid "Hide"
 msgstr "Скрыть"
 
 #: src/routes/builder/$resumeId/-sidebar/right/sections/page.tsx
-msgid "Hide all icons on the resume"
-msgstr "Скрыть все иконки в резюме"
+msgid "Hide Icons"
+msgstr "Скрыть значки"
 
 #. Accessible label for button that hides password in registration form
 #. Accessible label for button that hides password in reset-password form
@@ -1766,6 +1766,10 @@ msgstr "Скрыть все иконки в резюме"
 msgid "Hide password"
 msgstr "Скрыть пароль"
 
+#: src/routes/builder/$resumeId/-sidebar/right/sections/page.tsx
+msgid "Hide Section Icons"
+msgstr "Скрыть значки разделов"
+
 #. Impact severity label in resume analysis suggestion card
 #: src/routes/builder/$resumeId/-sidebar/right/sections/resume-analysis.tsx
 msgid "High"
@@ -1804,6 +1808,7 @@ msgid "Hungarian"
 msgstr "Венгерский"
 
 #: src/components/level/combobox.tsx
+#: src/dialogs/resume/sections/custom.tsx
 #: src/routes/builder/$resumeId/-sidebar/right/sections/design.tsx
 msgid "Icon"
 msgstr "Иконка"
@@ -3991,4 +3996,3 @@ msgstr "Уменьшить"
 #: src/libs/locale.ts
 msgid "Zulu"
 msgstr "Зулу"
-