docs: document RepeaterBook CSV integration + live-verified CI-V findings

DECISIONS.md

@@ -22,6 +22,23 @@ Format: `YYYY-MM-DD: <decision> — <why>`
 - 2026-06-14: Aesthetic = industrial instrument faceplate (amber VFD via DSEG7 font,
   LED S-meter, illuminated mode buttons) — matches the radio-gear domain and the
   Sethian dark/orange brand. Verified by headless screenshot.
+- 2026-06-14: RepeaterBook integration — local `repeaters.json` + a proximity-ordered
+  panel "Repeaters" card; tapping a row tunes the radio (freq + duplex + tone) over
+  CI-V. Operating convenience without per-request API calls.
+- 2026-06-14: CSV-only data path (dropped the token-gated API client + systemd timer).
+  RepeaterBook's API is now auth-gated (`401 auth_missing`, manual app-token approval);
+  Seth supplied a CSV proximity export instead, so manual re-ingest is enough (YAGNI).
+- 2026-06-14: No lat/long in the CSV → rank by file order (RepeaterBook's own proximity
+  sort) instead of haversine. The export is already nearest-first; geocoding is overkill.
+- 2026-06-14: Mixed FM+DSTAR repeaters labeled FM (operable as analog now); pure DSTAR
+  labeled DV (freq/offset only — call routing is set on the head).
+- 2026-06-14: **Live CI-V verification of repeater commands.** Verified on the rig:
+  duplex direction `0x0F` (read → 0x10 simplex), repeater tone `0x1B/00`, tone-switch
+  `0x16/42`. The tone field is 3 bytes on the wire (`00` pad + 2-byte BCD, e.g.
+  `00 08 85` = 88.5 Hz) — radio.py adds/strips the pad. A full `tune_repeater` to a live
+  repeater ACKed every step. Offset *amount* cmd `0x0D` is **rejected (NG)** by the
+  ID-5100 → removed; the radio applies its configured auto-offset when a duplex
+  direction is selected, so standard (0.6/5 MHz) repeaters work from duplex alone.
 
 ## Deferred / Rejected
 
@@ -33,3 +50,10 @@ Format: `YYYY-MM-DD: <decision> — <why>`
   as trusted until confirmed against the manual's CI-V table or the live rig.
 - **RS-MS1A data-jack protocol (D-STAR DR/callsign/messaging)** — out of scope for
   this CI-V layer; separate effort if wanted.
+- **RepeaterBook API client + daily systemd refresh** — deferred (CSV-only chosen);
+  revive if hands-off refresh is wanted. The token-request form text is in the design
+  spec under `docs/superpowers/specs/`.
+- **CI-V offset-amount control** — rejected: the ID-5100 NGs cmd `0x0D`. Offset amount
+  is a radio-side config (auto-offset); only direction (DUP±) is settable over CI-V.
+- **Distance/haversine ranking** — rejected for the CSV path: the export has no
+  lat/long and is already proximity-sorted, so file order is the rank.