fix(usps): support USPS v2 progress-bar tracking page

[WolffRuoff]

Problem

USPS scrapes started failing with a wait_for_selector timeout on .track-statusbar:

Page load failed ... selector='.track-statusbar'
  redirected_to=https://tools.usps.com/tracking/9434637902900031932314

USPS migrated its tracking page — …/go/TrackConfirmAction now 302-redirects to a new …/tracking/ page. The new DOM dropped the .track-statusbar wait selector and the .current-tracking-status-wrapper status banner, so the scrape timed out before parsing and returned no data. (The bot_service=Akamai Bot Manager line in the log is a separate IP-dependent variant; the deployment hitting this bug reaches real content fine.)

Fix

Support both layouts instead of swapping one for the other:

• v1 — legacy widget (.track-statusbar / .current-tracking-status-wrapper)
• v2 — progress bar (.tracking-progress-bar-status-container)

Robustness against future CSS churn

The redesign renamed the wrapper classes but kept the leaf classes (.tb-step, .tb-status, .tb-status-detail, .tb-date, .tb-location, .expected_delivery, .eta_snip). So parsing now anchors on the stable leaves and treats wrappers as optional — a future "v3" wrapper rename should need no code changes.

• WAIT_SELECTOR waits on leaf classes + the known wrappers
• status derives from leaf status text, with the v2 <state>-status container modifier class as a fallback
• events select .tb-step directly (wrapper-independent), with dedup
• _parse_date strips the clock time now on event dates ("July 8, 2026 9:49 AM") and no longer corrupts the weekday "Monday" (a bare "on" match); event description now prefers .tb-status-detail

Note: an embedded-JSON approach (à la SpeedX) was considered for maximum durability, but the new USPS page is server-rendered with no JSON/state blob (grep found no ld+json / __INITIAL_STATE__), so leaf-anchoring is the durable ceiling here.

Testing

• New v2 fixtures (v2_in_transit.html, v2_delivered.html) built from a real captured page, plus a TestParseV2ProgressBarLayout suite and _parse_date regression tests.
• Full scraper suite: 187 passed.

🤖 Generated with Claude Code