When source == "jobgether", build_prompt() injects a recruiter context
note directing the LLM to address the Jobgether recruiter using
"Your client [at {company}] will appreciate..." framing rather than
addressing the employer directly. generate() and task_runner both
thread the is_jobgether flag through automatically.
- generate() accepts previous_result + feedback; appends both to LLM prompt
- task_runner cover_letter handler parses params JSON, passes fields through
- Apply Workspace: "Refine with Feedback" expander with text area + Regenerate
button; only shown when a draft exists; clears feedback after submitting
- 8 new tests (TestGenerateRefinement + TestTaskRunnerCoverLetterParams)
