Make app vehicle-agnostic: JSON vehicle profiles + menu bar

Vehicle data is now DATA, not code. PIDs/scaling/DTCs/presets live in
profiles/*.json; the app loads them at runtime, so it works across vehicles
and others can contribute profiles (open source).

Core:
- obdcore/formula.py: safe AST evaluator for scaling formulas (A/B/... byte
  vars, Torque/FORScan convention). Only arithmetic/bitwise + min/max/abs/
  round/int/float; names/attrs/arbitrary calls rejected at load -> a community
  profile CANNOT execute code.
- obdcore/profile.py: load/save/list profiles; compiles each formula into a
  decode callable. registry.py now profile-backed (PidRegistry/DtcDatabase
  take a Profile); hardcoded Ford table removed.
- store.py: clear()/snapshot()/export_csv() for capture management.

Profiles:
- profiles/ford-6.0-powerstroke.json (27 PIDs, verified formulas, DTCs)
- profiles/generic-obd2.json (standard SAE Mode-01 base, any vehicle)
- profiles/README.md (schema + formula language + contributing)

GUI:
- Menu bar: File (new/record/export/replay capture, quit), Profile (switch/
  load/import/reload/edit-JSON/export, live profile list), View (Graph/Table
  views, gauges P2, toggle PID dock, normalize, light/dark theme), Help
  (about/confidence legend/profile info).
- PID browser + presets rebuild on profile switch; added Table view; raw-JSON
  profile editor dialog (validates schema+formulas before saving).

Tests: profiles load+compile, formula sandbox rejects hostile input, decoders
still match real truck bytes, crank/derived/dead-PID/replay -- all pass.

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

gui/controller.py

@@ -6,7 +6,8 @@ a timer; the scheduler thread does the serial work.
 """
 import time
 
-from obdcore import PidRegistry, TimeSeriesStore, PollScheduler, CsvRecorder
+from obdcore import (PidRegistry, DtcDatabase, TimeSeriesStore, PollScheduler,
+                     CsvRecorder, load_default, load_profile)
 from obdcore.mock import MockLink
 
 # default poll rates (Hz) -- fast for the no-start metrics, slower for the rest
@@ -17,13 +18,21 @@ FAST_HZ = 5
 
 class Controller:
     def __init__(self):
-        self.reg = PidRegistry()
+        self.profile = load_default()
+        self.reg = PidRegistry(self.profile)
+        self.dtcdb = DtcDatabase(self.profile)
         self.store = TimeSeriesStore()
         self.link = None
         self.sched = None
         self.t0 = None
         self.connected = False
 
+    def load_profile(self, path):
+        """Switch the active vehicle profile (only allowed while disconnected)."""
+        self.profile = load_profile(path)
+        self.reg = PidRegistry(self.profile)
+        self.dtcdb = DtcDatabase(self.profile)
+
     def connect(self, port=None, baud=38400, mock=False):
         if mock:
             self.link = MockLink(clock=time.time)