G1000: deepen VNAV/PFD — V-DEV & VS-TGT chevrons, GPS phase, designated toggle

- PFD VNAV: magenta flight-plan target altitude on the alt scale (S.110), V DEV
  deviation scale + chevron (left, shown in VNAV when not on an ILS), VS TGT
  chevron on the VSI (S.113)
- GPS phase annunciation is now dynamic: APR (approach leg) / TERM (<30 nm to
  destination) / ENR, instead of a fixed label
- flight-plan ALT can be toggled designated(blue) <-> reference(white) by clicking
  the cell (S.106); only designated altitudes drive the VNAV profile
- setPlan now preserves the dsgn/appr waypoint flags across the shared plan
- AFCS vertical mode labelled VPTH (manual) instead of VNV

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/styles.css

@@ -248,7 +248,9 @@ body {
 .r-wpt b { font-weight: 700; } .r-wpt b.cur { background: #19b8e6; color: #042230; padding: 0 4px; border-radius: 1px; }
 .r-dtk, .r-dis, .r-cum { color: #e7edf2; text-align: right; }
 .r-alt { color: #6f808d; text-align: right; }
+.r-alt { cursor: pointer; }
 .r-alt.dsgn { color: #4fa8ff; }   /* designated (VNAV) altitude = blue, per manual S.105 */
+.r-alt.refr { color: #e7edf2; }   /* reference altitude = white (not in the VNAV profile) */
 /* CURRENT VNV PROFILE panel (MFD flight-plan page) */
 .fpl-vnav { border-top: 1px solid #2c343c; padding: 6px 12px 8px; font-family: 'Roboto Mono', monospace; }
 .fpl-vnav-h { color: #36d2ff; font-size: 11px; letter-spacing: 1px; margin-bottom: 5px; }