refactor: unify section content types between types.ts and component-local definitions

[aafre]

Section content types (ExperienceItem, EducationItem, and icon list items) are defined in two places with inconsistent fields, causing TypeScript incompatibilities.

  types.ts (shared)

  export interface ExperienceItem {
    company: string;
    title: string;
    dates: string;
    description: string[];
    icon?: string;              // string | undefined only
  }

  export interface EducationItem {
    degree: string;
    school: string;
    year: string;
    field_of_study?: string;
    icon?: string;              // string | undefined only
  }

  export interface IconListItem {
    certification: string;
    issuer: string;
    date: string;
    icon: string;               // required, non-nullable
  }

Component-local definitions

Each component defines its own version with extra fields:

ExperienceSection.tsx — local ExperienceItem:

• icon?: string | null (allows null)
• iconFile?: File | null (extra)
• iconBase64?: string | null (extra)

EducationSection.tsx — local EducationItem:

• icon?: string | null (allows null)
• iconFile?: File | null (extra)
• iconBase64?: string | null (extra)

IconListSection.tsx — local Certification:

• icon?: string | null (optional + nullable vs required)
• iconFile?: File | null (extra)
• iconBase64?: string | null (extra)

Impact

This type drift caused a build failure (TS2322) in SectionRenderer.tsx when the onUpdate callback was typed as Section['content']. The component-local types are not assignable to the types.ts union because of the null icon values and extra fields. Currently worked around with unknown typing in PR #245.

Proposed Solution

1. Update types.ts to be the single source of truth — add iconFile, iconBase64, and allow null on icon fields
2. Remove the duplicate local interfaces from ExperienceSection.tsx, EducationSection.tsx, and IconListSection.tsx — import from types.ts instead
3. Update SectionRenderer.tsx onUpdate callback type from unknown back to Section['content']
4. Verify all tests and build pass

Acceptance Criteria

• No duplicate type definitions for section content items
• All section content types imported from types.ts
• SectionRenderer.onUpdate uses Section['content'] (not unknown)
• npm run build passes
• npm test passes (all 1195+ tests)

Related

• PR fix(editor): correct SectionRenderer onUpdate type to fix build #245 — build fix using unknown workaround
• PR perf(editor): optimize editor rendering performance #230 — Jules' SectionRenderer introduction (where the type mismatch originated)