feat: add /setup_docs, /reset, /expand commands and /upskill skill

Adds four contributions from @Michael-Bach:

- /setup_docs - document-driven profile population from a documents/ folder (CV, LinkedIn export, diplomas, references, past applications). Idempotent merge with explicit additive vs. conflicting buckets and per-conflict prompts.
- /reset - typed-RESET confirmation gate for clearing profile data and/or documents folder contents.
- /expand - additive competency enrichment from documents and public URLs already in the profile (GitHub repos, portfolio sites), with web-searched syllabus lookups for named courses and certifications.
- /upskill - skill-gap analysis vs tracked jobs (or single URL), produces a prioritized heatmap and learning plan with year-tagged WebSearch queries.

Also adds the documents/ folder convention with README and gitignore entries for personal output files.

Closes #6

.gitignore

@@ -44,3 +44,26 @@ Thumbs.db
 
 # Skills lock (auto-generated)
 skills-lock.json
+
+# Personal application output files (generated by /apply — do not share)
+cv/main_*.tex
+!cv/main_example.tex
+cover_letters/cover_*.tex
+cover_letters/Cover_*.tex
+
+# documents/ subfolder contents are personal — only README and folder structure are tracked
+documents/cv/**
+documents/linkedin/**
+documents/diplomas/**
+documents/references/**
+documents/applications/**
+!documents/**/.gitkeep
+
+# Personal job search tracking
+job_search_tracker.csv
+
+# Upskill reports (personal output)
+upskill/*.md
+
+# Agent usage logs
+.agents/