List open Redmine issues assigned to the current (or overridden) user,
sorted by priority rank (P1..P5) then version due date with a stable id
tie-break. Renders an OSC 8 hyperlinked console table on stdout and a
counts/hours summary line on stderr; version due dates are fetched once
per unique version, unavailable versions degrade to an empty due date.
Also migrates the codebase to ruff 0.17.3 defaults (PEP 585/604
annotations, targeted noqa for intentional blind excepts and CLI root
logging). Behavior-neutral: 408 tests pass with -W error.
- Load time entry activity names from Redmine enumeration.
- Aggregate hours per issue and per activity in fetch_issues_with_spent_time.
- Add --by-activity CLI flag and propagate it through report builder,
summary, and all formatters (console, CSV, HTML, JSON, ODT).
- Keep backward-compatible 2-tuple input in build_grouped_report.
- Bump version to 1.8.0.
Closes#41
