feat: add /interview command for stage-specific interview prep from the application archive (#58)

07-interview-prep.md holds STAR examples, tough-question patterns,
questions to ask, and a roleplay protocol - and the job-application-
assistant skill names interview preparation as its Step 4 - but no
command operationalizes any of it. /apply ends at 'files ready', and the
moment an interview is scheduled, nothing picks the thread back up.
/interview does, drawing on the archive /outcome now maintains.

/apply optimizes what the company reads; /interview optimizes what the
company hears. The bridge is consistency: the interviewer read the
submitted CV and cover letter, so prep must match what they claim.

How it works:

- Loads the application context from documents/applications/
  <company>_<role>/: the exact posting, the submitted drafts, and
  outcome.md's stage + recorded feedback (stage-N feedback is the
  highest-priority input for stage-N+1 prep). Graceful fallbacks for
  applications that predate /outcome, stating plainly what is missing
- Runs the Company Research Checklist that 04-job-evaluation.md defines
  but nothing executes, plus interviewer-angle notes from public
  professional info only. Every company claim is independently verified
  before it enters the pack - same rule as cover-letter claims
- Builds a stage-specific prep pack: likely questions (earlier-stage
  feedback first, then fit-evaluation gaps with honest bridge answers
  per 07's you-don't-have-X pattern, then posting requirements, then
  stage type), STAR mapping via 07's Use-for tags with new drafts
  grounded strictly in profile facts, a consistency brief of the
  submitted documents' probeable claims, customized tough questions,
  4-6 questions to ask, logistics tips
- Saves the pack to documents/applications/<company>_<role>/
  interview_prep_<stage>.md - one per stage, kept as history,
  gitignored with the rest of the archive
- Offers a mock interview following 07's Roleplay Guidelines verbatim,
  with feedback calibrated against the behavioral profile (same
  voice-consistency rule the /apply reviewer applies)
- Never edits framework or profile files, except appending
  user-approved STAR examples to 07 on explicit request

Integration: /outcome suggests /interview when an interview stage is
recorded; documents/README.md documents the interview_prep_<stage>.md
files (and that /setup ignores them); README commands list and file
tree.

README.md

@@ -99,8 +99,9 @@ This runs the full workflow: evaluate fit, draft CV + cover letter, review with
 
 ## Other commands
 
-`/setup`, `/scrape`, and `/apply` form the core workflow. Six more commands extend it once your profile is in place:
+`/setup`, `/scrape`, and `/apply` form the core workflow. Seven more commands extend it once your profile is in place:
 
+- **`/interview`** preps you for a scheduled interview on a tracked application. It builds a stage-specific prep pack from the application's archive (the exact posting, the CV and cover letter the interviewer actually read, feedback recorded from earlier rounds), researches the company and interviewers with a verify-before-use rule, maps likely questions to your STAR examples, and offers a mock interview following the roleplay protocol in `07-interview-prep.md`. Gaps get honest bridge answers, never invented experience.
 - **`/outcome`** records what happened to an application - interview stages, offers, rejections, silence. It archives the submitted CV, cover letter, and posting text into `documents/applications/<company>_<role>/`, keeps `outcome.md` in the format `/setup` Path A parses, and updates the tracker. Once a few applications resolve, it points you back to `/setup` to calibrate the fit framework from what actually got interviews.
 - **`/rank`** bridges `/scrape` and `/apply`: it batch-scores all newly scraped postings against the fit framework (parallel agents fetch each posting and score the five evaluation dimensions) and returns a ranked shortlist with honest per-job strengths and gaps. Deal-breakers veto, deadlines get urgency flags, dead postings get marked expired. Pick a number and it hands off to the full `/apply` workflow.
 - **`/expand`** enriches your profile by scanning public sources you've already linked in it (GitHub repos, portfolio site, Kaggle, Google Scholar) and looking up syllabi for named courses and certifications. Discovered competencies are added to your profile with a source tag. Useful right after `/setup` to surface skills that documents alone don't make explicit.
@@ -124,6 +125,7 @@ ai-job-search/
 │   │   ├── add-portal.md              # /add-portal generate a job-portal search skill for your market
 │   │   ├── rank.md                    # /rank triage scraped jobs into a ranked shortlist
 │   │   ├── outcome.md                 # /outcome record application results, archive materials
+│   │   ├── interview.md               # /interview stage-specific prep pack + mock interview
 │   │   └── reset.md                   # /reset wipe profile data or documents folder
 │   ├── skills/
 │   │   ├── job-application-assistant/  # Core application skill