v3.13.7 — multi-account cross-contamination fix, honest projections under heavy burn, same-hue gradient fill

Fixed

• Parallel sessions logged into different Claude accounts no longer
  cross-contaminate the 5h/7d display. The statusline stdin blob does not
  identify which account produced it, so with multiple accounts running
  side-by-side, ALL sessions wrote into the current login's shared store — and
  the "later resets_at wins" merge let another account's 7d window mask the
  real one with no heal path (live incident: bar showed the other account's
  7d 14% while /usage said 77%). A reading's identity is now
  (window, resets_at): the shared store keeps per-reset buckets, each render
  is answered from the bucket matching its OWN blob's reset, and all
  v3.13.3–v3.13.5 healing rules (monotonic merge, confirmation grace,
  re-baseline acceptance) apply unchanged within a bucket. Legacy store
  schemas migrate automatically.
• →NN% projections were artificially conservative during heavy use.
  Three stacked causes: (1) the cross-account bug above also starved the real
  window's projection samples (samples for an earlier-reset window were
  rejected outright — the live window had 2 samples in 28h, leaving →NN% on
  cold priors); (2) a flat 20%/h plausibility cap silently rejected genuine
  heavy parallel-session burn (observed 37%/h on the 5h window), so the
  "recent rate" never existed exactly when it mattered — caps are per-window
  now (5h 60%/h, 7d 10%/h) with a ≥300s observation-span floor as the glitch
  filter; (3) the 7d projection ignored current momentum entirely — the rate
  measured over the last 3h now carries the next ≤3h (it can only raise the
  bucket estimate, never lower it).

Changed

• Battery bar fill is now a same-hue gradient. The left cell anchors the
  exact severity colour (green/yellow/red semantics unchanged), fading darker
  toward the progress tip by scaling toward black — hue stays rich, the tip
  melts softly into the empty section, and a lone filled cell stays pure
  colour. Bar frame, ⏰, separators and all classic identity elements are
  untouched.