fix(abcip): native runtime STRING capacity, mistype churn, malformed-name config error, LWORD type check; non-blocking lease release (#570, #579)

#570
- STRING: the built-in 88-byte Logix STRING holds 82 characters (LEN + DATA[82] + 2 pad), not 84; the
  write still sends the whole 88-byte structure and a read never decodes the pad as characters.
- Mistype churn: a type refusal (CIP 0xFF/0x2107) on the existence read no longer throws from
  InitializeAsync, so the runtime is not disposed/re-created (and re-Forward-Opened) every poll; the driver
  also keeps a runtime that throws TypeMismatch from init and records the device as reachable.
- Malformed tag name: a TagPath that does not parse, or a name the CIP symbolic encoder refuses (now also
  non-ASCII, empty member, >255-char member, unterminated subscript), is AbCipTagConfigurationException ->
  per-tag BadConfigurationError (named const in AbCipStatusMapper), warned once, never feeding the device
  backoff or health; siblings keep reading. A malformed probe tag no longer feeds the backoff either.
- Micro800 BYTE/WORD/LWORD (0xD1/0xD2/0xD4) are type-checked as integers of their width: REAL/LREAL or a
  narrower integer over LWORD is TypeMismatch, not decoded garbage.

#579
- ConnectionLease.ReleaseInBackground: one non-blocking release shape for both native AB runtimes. The
  AbCip runtime's Dispose no longer waits up to 2 s under the per-tag lock; the pool still registers the
  close synchronously so a re-create cannot overlap it. Offline soak tests (25 cycles, AbCip + AbLegacy)
  prove no leaked connection; FakeEipServer gains OpenConnections.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

docs/drivers/AbLegacy.md

@@ -150,6 +150,9 @@ Native routing: SLC500/MicroLogix/PLC-5 are direct; `logixpccc` uses Unconnected
   - **ST (string) byte order is unverified** (no capture); string values may be byte-swapped.
   - Unlike AbCip, the native AbLegacy runtime has **no element-type check**, so a mis-authored same-width
     type reads as reinterpreted data (as on libplctag), not `BadTypeMismatch`.
+  - Releasing a native tag (evict, reinitialize, shutdown) never blocks on the connection close: the lease
+    is released in the background (`ConnectionLease.ReleaseInBackground`), the same shape as native AbCip
+    (#579). A re-create cannot overlap the close, because the pool holds the successor connection behind it.
 
 ### Wire evidence (native PCCC)