v0.3.0

Summary
claudelog with no arguments runs a default
report (--week) instead of printing usage
Default flags configurable via defaultReport
in config.json
Added full open source community files:
CONTRIBUTING.md, SECURITY.md, CHANGELOG.md,
issue templates, PR template
Changes
Default report (bin/claudelog, lib/config.mjs)

No-arg invocation dispatches to report.mjs
with ["--week"]
New defaultReport config option: array of
CLI flags passed to report
Validation: must be array of strings, falls
back to ["--week"] on invalid config
Community files

CONTRIBUTING.md — setup, code style, TDD,
PR process, conventional commits
SECURITY.md — vulnerability reporting via
GitHub Security Advisories or email
CHANGELOG.md — retroactive entries for
0.1.0, 0.2.0, and unreleased changes
.github/ISSUE_TEMPLATE/bug_report.md
.github/ISSUE_TEMPLATE/feature_request.md
.github/PULL_REQUEST_TEMPLATE.md
Docs (README.md, config.example.json)

CLI usage section updated with default report
defaultReport documented in configuration
Version bump to 0.3.0