docs(epic-3): add tech spec and story drafts for PDF Export

Epic 3: PDF Export - Planning Phase Complete

Tech Spec:
- Create tech-spec-epic-3.md with 10 acceptance criteria
- Define API contracts, workflows, and NFRs
- Document dependencies (puppeteer, @sparticuz/chromium)
- Add Vercel deployment configuration
- Include traceability mapping and test strategy

Story Drafts:
- 3-1: Create PDF Generation API Route (8 ACs, Puppeteer integration)
- 3-2: Create PDF Download Composable (8 ACs, download logic)
- 3-3: Connect Download Button to PDF Generation (8 ACs, integration)

Sprint Status Updates:
- epic-3: backlog → contexted
- All 3 stories: backlog → drafted

Files Created:
- docs/sprint-artifacts/tech-spec-epic-3.md
- docs/sprint-artifacts/3-1-create-pdf-generation-api-route.md
- docs/sprint-artifacts/3-2-create-pdf-download-composable.md
- docs/sprint-artifacts/3-3-connect-download-button-to-pdf-generation.md

Files Modified:
- docs/sprint-artifacts/sprint-status.yaml

Ready for: Story context generation or implementation

docs/sprint-artifacts/3-2-create-pdf-download-composable.md

@@ -0,0 +1,171 @@
+# Story 3.2: Create PDF Download Composable
+
+Status: drafted
+
+## Story
+
+As a developer,
+I want a composable that handles PDF download logic,
+so that the download button can trigger downloads easily.
+
+## Acceptance Criteria
+
+1. **AC1:** Given I call `downloadPdf()` from the composable, when the function executes, then it fetches `/api/resume/pdf` as blob
+2. **AC2:** The composable creates object URL from blob and triggers browser download
+3. **AC3:** Download filename is from `getPdfFilename()` (e.g., "Ali_Arghyani_Resume.pdf")
+4. **AC4:** The composable returns `isGenerating: Ref<boolean>` for loading state
+5. **AC5:** The composable returns `downloadPdf: () => Promise<void>` function
+6. **AC6:** Given an error occurs, when caught, then it shows toast notification with error message
+7. **AC7:** After error, `isGenerating` is set back to false
+8. **AC8:** Object URL is revoked after download to prevent memory leaks
+
+## Tasks / Subtasks
+
+- [ ] Create composable file (AC: #4, #5)
+  - [ ] Create `app/composables/useResumePdf.ts`
+  - [ ] Define `isGenerating` ref with initial value false
+  - [ ] Define `downloadPdf` async function
+  - [ ] Return both from composable
+
+- [ ] Implement download logic (AC: #1-#3, #8)
+  - [ ] Set `isGenerating = true` at start
+  - [ ] Fetch `/api/resume/pdf` with `responseType: 'blob'`
+  - [ ] Create object URL from blob: `URL.createObjectURL(response)`
+  - [ ] Create temporary `<a>` element
+  - [ ] Set `href` to object URL
+  - [ ] Set `download` attribute to filename from `getPdfFilename()`
+  - [ ] Trigger click on element
+  - [ ] Revoke object URL: `URL.revokeObjectURL(url)`
+  - [ ] Set `isGenerating = false` in finally block
+
+- [ ] Add error handling (AC: #6, #7)
+  - [ ] Wrap in try-catch block
+  - [ ] Import `useToast()` from Nuxt UI
+  - [ ] Show error toast on catch
+  - [ ] Log error to console
+  - [ ] Ensure `isGenerating = false` in finally
+
+- [ ] Test composable
+  - [ ] Import in component and call `downloadPdf()`
+  - [ ] Verify loading state changes
+  - [ ] Verify file downloads with correct name
+  - [ ] Test error handling (disconnect network)
+
+## Dev Notes
+
+### Architecture Alignment
+
+**From Architecture Doc:**
+- File location: `app/composables/useResumePdf.ts`
+- Uses `$fetch` with blob response type
+- Uses Nuxt UI `useToast()` for notifications
+- Gets filename from `useResumeData().getPdfFilename()`
+
+**From Tech Spec Epic 3:**
+- AC5-AC7 map to this story
+- Composable interface defined in spec
+
+### Implementation Notes
+
+**Composable Structure:**
+```typescript
+export function useResumePdf() {
+  const isGenerating = ref(false)
+  const toast = useToast()
+  const { getPdfFilename } = useResumeData()
+
+  async function downloadPdf() {
+    isGenerating.value = true
+    try {
+      const response = await $fetch('/api/resume/pdf', {
+        responseType: 'blob'
+      })
+      
+      const url = URL.createObjectURL(response)
+      const a = document.createElement('a')
+      a.href = url
+      a.download = getPdfFilename()
+      a.click()
+      URL.revokeObjectURL(url)
+    } catch (error) {
+      console.error('PDF generation failed:', error)
+      toast.add({
+        title: 'Error generating PDF',
+        description: 'Please try again',
+        color: 'error'
+      })
+    } finally {
+      isGenerating.value = false
+    }
+  }
+
+  return { isGenerating, downloadPdf }
+}
+```
+
+**Usage in Component:**
+```vue
+<script setup>
+const { isGenerating, downloadPdf } = useResumePdf()
+</script>
+
+<template>
+  <UButton
+    :loading="isGenerating"
+    :disabled="isGenerating"
+    @click="downloadPdf"
+  >
+    Download PDF
+  </UButton>
+</template>
+```
+
+### Dependencies
+
+- `useResumeData()` composable (Epic 1) - for `getPdfFilename()`
+- `useToast()` from Nuxt UI - for error notifications
+- `$fetch` from Nuxt - for API calls
+
+### Testing Checklist
+
+- [ ] Composable exports `isGenerating` and `downloadPdf`
+- [ ] `isGenerating` starts as false
+- [ ] `isGenerating` becomes true during download
+- [ ] `isGenerating` returns to false after completion
+- [ ] PDF downloads with correct filename
+- [ ] Error shows toast notification
+- [ ] Error logs to console
+- [ ] `isGenerating` returns to false after error
+
+### References
+
+- [Source: docs/architecture.md#Error-Handling]
+- [Source: docs/architecture.md#Implementation-Patterns]
+- [Source: docs/sprint-artifacts/tech-spec-epic-3.md#AC5-AC7]
+
+## Dev Agent Record
+
+### Context Reference
+
+<!-- Will be filled by SM agent -->
+
+### Agent Model Used
+
+<!-- Will be filled by dev agent -->
+
+### Debug Log References
+
+<!-- Will be filled by dev agent during implementation -->
+
+### Completion Notes List
+
+<!-- Will be filled by dev agent after completion -->
+
+### File List
+
+<!-- Will be filled by dev agent with created/modified files -->
+
+---
+
+**Change Log:**
+- 2025-12-01: Story drafted by SM agent (Bob)