refactor(web): share charts, pagination, and progress views

[reneklacan]

The dashboard repeats chart rendering, pagination assembly, and progress parsing across several pages. Share these implementations within oxana-web while preserving the public Rust API, routes, and displayed behavior. This removes 400 lines overall.

• Extract shared chart styles, line and stacked-bar renderers, and tooltip handling while retaining each page's formatting and series ordering.
• Use one private pagination model for queue, scheduled, dead, and retry lists, preserving the 50-job page size and lookahead behavior.
• Parse and format progress once per rendered component, preserving notes, ETA, escaping, and fallback state display.

Validation:

• cargo fmt --all -- --check
• cargo clippy --all-features --workspace --all-targets -- -D warnings
• cargo test -p oxana-web --lib --quiet: 67 tests passed, including new pagination and progress regressions.
• Temporary verification harnesses: 108 old/new chart scenarios matched and 34 HTTP checks passed against isolated Redis data. The harnesses are outside the repository; they add no project dependencies.

Visual browser verification was unavailable because this host has no attached browser panes.

---

Note

Low Risk
Refactor-only changes to templates and private web helpers with regression tests; no auth, storage API, or routing changes beyond equivalent pagination assembly.

Overview
Consolidates repeated oxana-web dashboard logic so charting, job list paging, and in-job progress UI share one implementation while keeping routes and on-screen behavior the same.

Job progress replaces several Askama filters (show_job_progress, percent/summary/note/ETA) with a single job_progress filter that returns an optional ProgressView. Templates branch on Some(progress) and _job_progress.html reads preformatted fields, with new unit tests for tuple/object states, percent clamping, and HTML escaping of notes.

Pagination introduces JobPage (list_opts, 50-item pages + one lookahead row, has_next, range labels). Scheduled, dead, retry, and queue detail handlers route through global_jobs or JobPage::new instead of duplicating truncate/offset logic; list templates use page.jobs, page.number, and page.has_next.

Charts move uPlot assets, tooltip styling, line charts, and stacked bar rendering into _chart_head.html and _charts.html (oxanaCharts). Metrics, metric detail, and queues pages keep their formatters and series but drop large inline script blocks in favor of thin page-specific init code.

^{Reviewed by Cursor Bugbot for commit 326c311. Bugbot is set up for automated code reviews on this repo. Configure here.}