Commit tune maps and research so tunes are reachable from the phone

Removes the *.hex/maps_cache gitignore rule (explicit user call, reversing
the earlier no-redistribution stance) so the official TuneECU catalogue
maps, derived SAI/O2-delete composites, and the checksum/composition
tooling are actually available to pull up on a phone browser when using
the real TuneECU app. Also folds in tonight's KWP2000 fixes (TesterPresent
keep-alive, connect-failure cleanup, slow-init StartCommunication fix) and
the accumulated research docs.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FP2GaxS9HkUdL5sLBnjKje

tunie/research/EXTERNAL_RESEARCH_NOTES.md

@@ -0,0 +1,58 @@
+# External research pass — verified findings only (Aug 2026)
+
+A web-research agent was dispatched with a brief covering this project's
+open questions. Its raw report contained real value mixed with fabricated
+detail (invented a table-category split not present in a cited source,
+guessed at least one dead URL). Everything below has been **independently
+re-verified by this project directly against the actual source** — the
+raw report and the dispatch brief that produced it have been deleted; this
+is the distilled, trustworthy result, not a summary of the report.
+
+## Confirmed
+
+**`0x53822` device flag — Purge Control Valve, strengthened.** TuneECU's
+own `tests.html` (this project's site mirror) lists a distinct, real
+testable entry: *"Purge Control Valve (Only bikes with charcoal
+canister) — Activate the purge valve, listen for a very quiet noise,"*
+right alongside its own separate SAI entry. Confirms Purge Valve is a real
+device on this ECU family with its own dedicated path — genuinely
+strengthens (doesn't prove) the leading hypothesis for this byte. Also
+confirms "Air Flap (675 Daytona)" is Daytona-675-specific, per the same
+list. Full detail and remaining uncertainty: `reference-maps/DEVICES.md`.
+
+**Wideband sensor bung masking is real and worth designing around.**
+Confirmed via a real installer source (RB Racing): long/angled 18mm bungs
+and thread-reducing adapters (18mm→12mm) can prevent the sensor tip from
+reaching the core exhaust gas stream, causing delayed/inaccurate
+readings — *"Many manufacturers use long 18mm O2 slanted bungs. These
+'mask' the 18mm O2 sensor signal"*; thread reducers are *"junk... too long
+masking the signal."* Practical implication: check bung depth/angle
+against the sensor's spec before assuming any available bung (stock or
+new) works. Folded into `TUNING_IMPL_PLAN.md` Phase 2.
+
+**Zeitronix ZT-3 — a third real wideband option.** Sold by Woolich Racing
+as a tuning-package wideband kit. Adds to the existing list (Innovate
+LM-2/MTX-L, AEM X-Series UEGO). Folded into `TUNING_IMPL_PLAN.md` Phase 2.
+
+## Explicitly not carried forward (checked and rejected, or unverifiable)
+
+- A claimed "Speed-Density vs. Alpha-N" table split in a Keihin SH7054
+  XDF listing — checked the actual source, no such split exists there;
+  the page instead lists a 3-cylinder table set, meaning the wrong
+  product (likely a Triumph triple's XDF, not this twin) was cited.
+  Don't reuse this claim.
+- A specific Woolich Racing product URL for wideband bung fitment — the
+  exact URL doesn't resolve to a real distinct page; the general product
+  line exists but this project couldn't confirm it covers the correct
+  (Keihin, air-cooled) ECU generation rather than the later Bosch/
+  liquid-cooled T100. Same wrong-generation risk this project has hit
+  repeatedly elsewhere — don't cite this source without re-confirming
+  ECU generation first.
+- A Reddit thread claimed to discuss map `20262` availability — could not
+  be fetched or verified at all (Reddit blocks this project's tooling).
+- Claims about TTP's "TuneLoader" licensing mechanism and Ultimate Twin
+  Performance's remap-service pricing — plausible, not independently
+  checked.
+- A Manitoba emissions-inspection regulation citation — checked, the
+  specific regulation number cited does not match what's actually
+  findable; not relied on for anything, not detailed further here.