Add Certification & Licensure Packet V1

[mergemaven11]

What changed

• adds a Pro-gated Certification & Licensure Packet built on the existing career-evidence engine
• supports credential/license name, issuing or reviewing body, review type, and optional requirement notes as packet context
• organizes accomplishments, competencies, credential evidence, experience, and the evidence index around a review period
• classifies evidence as Self-added, Confirmed, or Organization-issued using existing BragStack trust signals
• explicitly avoids treating an uploaded certificate/license as independently verified without a confirmation or organization-issued signal
• adds a dedicated server-generated US Letter PDF and download filename
• adds frontend packet-builder controls and physical dossier preview pages
• adds certification_packet entitlements for Pro, Team, and Enterprise
• adds backend coverage using a cosmetology license-renewal scenario with all three evidence trust states

Career-neutral design

The packet does not add profession-specific fields to the core schema. It can support healthcare, education, skilled trades, beauty/cosmetology, public service, finance, safety, and other credential-heavy careers using the same accomplishment / receipt / evidence / skills model.

Validation target

• Backend CI
• Frontend ESLint
• Frontend production build
• Free-plan entitlement rejection
• self-added vs confirmed vs organization-issued evidence classification
• real certification/licensure PDF generation

Closes #28.