Resume tailoring should add keywords to Work Experience bullets

Let resume tailoring add keywords to Work Experience bullets, not just Skills

When tailoring a resume to a job, missing keywords are currently added only to the Skills section while the Work Experience bullets stay unchanged. Recruiters look for evidence of where a skill was used, so a keyword in a list helps less than one inside a bullet. Requested changes:

1. A toggle in the tailor flow to choose where keywords go: Skills only, Experience bullets only, or both.

2. A preview of each bullet change so it can be accepted or rejected before saving.