- Extract PathParser.valid_callsign?/1 and reuse from the calibration
Mix task instead of duplicating the regex.
- Document raise behavior on Aprs.recent_packets_with_paths/1 and
Aprs.station_positions/1 (already noted in moduledoc; @doc reinforces
for callers reading the function head).
- Note in the BandConfig guard comment why it sits before the Oban pause
(so a misconfig exits without leaving queues paused).
- Reword the band-mismatched-negatives note as a v1 limitation (no TODO
tag — codebase convention is zero TODOs).
Q-construct now matches the explicit APRS-IS set (qAC/qAX/qAU/qAo/qAO/
qAS/qAr/qAR/qAZ/qAI) instead of any qA[A-Za-z]. WIDE/TRACE n-N now allows
n and N up to 7 per the APRS New-N paradigm (was [12]).
Three spec-compliance fixes to PathParser:
1. Q-construct regex now accepts lowercase letters (qAo, qAr, etc.).
The moduledoc lists qAo as a Q-construct to skip but the previous
~r/^qA[A-Z]$/ rejected it, leaving it to be misclassified.
2. self_loop?/2 now compares callsigns only; the spurious
src_pos == dst_pos clause would falsely suppress two distinct
stations that happen to share coarse coordinates (e.g. same building).
3. Strengthen the "lookup returned nil → drop hop, do NOT advance source"
test: extend the path to three tokens so the assertion actually proves
the third hop chains from the previous good source rather than from
the dropped one. The two-token version passed regardless of behavior.
Self-loop fixture updated to trigger via callsign equality (the only
remaining mechanism) instead of position equality.
Pure-Elixir parser that walks an APRS digipeater path left-to-right and
emits verified hops for callsigns carrying the used flag (`*`). Filters
Q-constructs, TCPIP/TCPXX, and routing aliases (WIDE/TRACE/RELAY/etc.);
handles anonymous-digi cases, missing station-position lookups, and
self-loops without advancing source past unattributable hops.
Used by upcoming 144 MHz calibration to attribute aprs.me receives to
real digipeater geometry without persisting any APRS data on our side.
