Rename project to OBDash + per-metric colored multi-axis

Rename: the app is vehicle-agnostic, so 'ford-obd' was wrong. Rebranded all
code/docs/profile authors to OBDash; Gitea repo renamed justin/ford-obd ->
justin/obdash (remote + description updated). Ford the make and the
ford-6.0-powerstroke profile are unchanged (that vehicle really is a Ford).

Multi-axis upgrade (per request):
- MultiAxisPlot now gives each METRIC its own Y axis, each axis colored to
  match its line; the primary metric owns the LEFT axis, others stack right.
- Click a line to promote it to the left axis (sigClicked -> set_primary).
- Cleaner teardown (no removeItem warnings); axis label no longer doubles the
  unit; Normalize round-trips.

Validated headless: colored per-metric axes, promote-to-left, gauge view,
normalize toggle, profile switch; obdcore + diagnostics tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016yT89n4zR4qbrySoSiEyZs

profiles/ford-mustang-gt-4.6-1996.json

@@ -6,7 +6,7 @@
     "model": "Mustang GT",
     "years": "1996",
     "engine": "4.6L SOHC 2-valve modular V8 (EEC-V, MAF-metered)",
-    "author": "ford-obd project",
+    "author": "OBDash project",
     "version": "0.1.0",
     "protocol": "SAE J1850 PWM",
     "notes": "EEC-V PCM on SAE J1850 PWM (41.6 kbaud, OBD-II pins 2 & 10). MAF-metered V8 with dual exhaust: four heated O2 sensors (B1S1/B1S2/B2S1/B2S2) and two fuel-trim banks. Bank 1 = passenger side (cyl #1). Standard SAE J1979 Mode-01 backbone; no verifiable mode-22 enhanced PIDs published for this early EEC-V generation."