Phase 6: town-crier news (website -> game)

BridgeTownCrier handles inbound towncrier.add / towncrier.remove, pushing
website-published news into GlobalTownCrierEntryList so every town crier
announces it until it expires. Both run on the Core thread (required: AddEntry
mutates a shared list and the criers send packets). An id maps to the created
TownCrierEntry so a later remove can pull it, and re-adding an id replaces the
prior entry.

Caps are enforced before touching the shared list -- line count, line length,
active-entry count, duration -- as defense in depth on top of the loopback trust
boundary: a buggy or compromised sidecar still cannot flood the criers or pin a
message forever. Config: Bridge.TownCrierMax{Lines,LineLength,Active,DurationSec}.

Verified with a sending stub and a probe that logs the actual crier list. Replies
and game state agree: add n1 -> towncrier.ok and the entry appears with the exact
lines; add n2 (8 lines over the cap of 6) -> towncrier.error and never enters the
list; remove n1 -> towncrier.ok and the entry is gone; remove unknown ->
towncrier.error. Evidence in docs/PLAN.md §16.

Adds BridgeJson.GetStringList for JSON string arrays, tools/stub_sidecar_crier.ps1,
and tools/scaffolding/BridgeCrierProbe.cs. This closes the pure-plugin inbound
work; only the PlayerVendorSale core edit (Phase 7) remains on the ServUO side.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

overlay/Config/Bridge.cfg

@@ -22,6 +22,13 @@ EconomySweepSeconds=300
 # Shown to a player when they run [link. The website page where they enter the code.
 LinkUrl=https://yoursite/link
 
+# Town-crier news pushed from the website. Caps are defense in depth on top of the
+# loopback trust boundary: a buggy or compromised sidecar still cannot flood the criers.
+TownCrierMaxLines=6
+TownCrierMaxLineLength=200
+TownCrierMaxActive=20
+TownCrierMaxDurationSec=86400
+
 # The test scaffolding in tools/scaffolding/ reads its own flags from this file
 # (SeedOnStart, CensusOnStart, ProbeOnStart). They are absent here on purpose:
 # Config.Get returns the default of false when a key is missing, so a deployed