fix(validation): remove false positives from config validate/check

[s31teg]

Summary

On a real 2.4 MB house project, lox config validate and lox config check produced about 15,000 UUID warnings and about 750 wiring and layout findings. Almost all of it was noise, and it hid the few real problems. On the 41 sample configs in tests/eval/golden/configs, check failed on 40 of them for the same reasons. This PR removes those false positives and keeps the genuine cases.

Changes

validate

• Drop "UUID missing serial suffix". The last UUID group identifies the Loxone Config installation that created the element, not the Miniserver serial, and real projects mix dozens of suffixes. It is replaced by a shape check (8-4-4-16 hex; a shorter last group is allowed for system/mode UUIDs).
• Wiring-direction check: ignore links that Config manages itself (<In FLG="1">) and API connectors (API, OutputAPI). An API connector takes command text in, e.g. from a virtual text input, and reports status out.

check

• Missing canvas layout: only reported for direct children of a Page. Hidden InputRef / OutputRef / OutputRefLM without the 0x20000 "placed" bit are skipped. Nested elements (Keycodes in an NfcCodeTouch, meters in an EFM) never have coordinates. A normal block on a page without coordinates is still reported.
• Unwired inputs: no longer reported one by one. Most inputs are optional, and the schemas have no required-input data.
• "No inputs wired": only reported for pure logic blocks (And, Or, comparators, math, timers…). Controllers (LightController2, PushButton2, AutoJalousie, Central*, EFM…) are legitimately driven from the app, by time or by device binding.
• Skipped blocks: wiring checks now skip blocks that aren't on a Page, InputRef / OutputRef (fed by Ref, not by page wires) and AutoPilot / AutopilotRule (their conditions live in the APC JSON; their inputs are managed by Config).
• Comparator Input2: counts as set when it has a Def or at least one <In> wire. An empty GreaterEqual / Less threshold compares against 0, which can be intended (e.g. Loxone's own SG Ready sample tests "price below 0"), so it is now a warning instead of an error.

Results

Real project:

Command	Message	Before	After
validate	UUID missing serial suffix	14,802	0
validate	wired TO an Output connector	1	0
check	no inputs wired	493	0
check	unwired inputs	139	0
check	missing canvas layout	114	0
check	Input2 not set	3 (✗)	1 (⚠)

41 sample configs:

Command	Message	Before	After
validate	UUID missing serial suffix	20,627	0
validate	wired TO an Output connector	21	2 (Var1 / Var2, left as is)
check	no inputs wired	1,785	0
check	unwired inputs	144	0
check	missing canvas layout	135	0
check	files where check exits 0	1 / 41	41 / 41

Testing

• New unit tests, one per rule. Each covers the false-positive case and confirms the genuine case is still reported:

  • an unplaced block on a page;
  • an empty comparator threshold;
  • a malformed UUID.

  The tests for the original six fixes fail on main.

• cargo fmt --check, cargo clippy -- -D warnings, cargo build --release and cargo test pass.

Known gap

A controller with nothing wired at all (e.g. a forgotten LightController2) is no longer reported. A narrower warning for that case was tried, but nearly all of its hits on real data were legitimate, so it was left out.