fix(models): synthesize antigravity Gemini 3.1 pro high/low models (#22899)

* Models: add antigravity Gemini 3.1 forward-compat

* models: propagate availability to Gemini 3.1 dot IDs

* test(models): format Gemini 3.1 forward-compat test

* test(models): type Gemini 3.1 forward-compat fixtures

* models: add changelog note for antigravity gemini 3.1 forward-compat

---------

Co-authored-by: Vincent Koc <vincentkoc@ieee.org>

CHANGELOG.md

@@ -701,6 +701,7 @@ Docs: https://docs.openclaw.ai
 - Agents/Context: apply configured model `contextWindow` overrides after provider discovery so `lookupContextTokens()` honors operator config values (including discovery-failure paths). (#17404) Thanks @michaelbship and @vignesh07.
 - Agents/Context: derive `lookupContextTokens()` from auth-available model metadata and keep the smallest discovered context window for duplicate model ids, preventing cross-provider cache collisions from overestimating session context limits. (#17586) Thanks @githabideri and @vignesh07.
 - Agents/OpenAI: force `store=true` for direct OpenAI Responses/Codex runs to preserve multi-turn server-side conversation state, while leaving proxy/non-OpenAI endpoints unchanged. (#16803) Thanks @mark9232 and @vignesh07.
+- Models/Antigravity: synthesize Gemini 3.1 Pro high/low model IDs (dash and dot forms) from Gemini 3 templates so `models list` and `/model` remain usable while upstream catalogs catch up. (#22492) Thanks @Phineas1500.
 - Memory/FTS: make `buildFtsQuery` Unicode-aware so non-ASCII queries (including CJK) produce keyword tokens instead of falling back to vector-only search. (#17672) Thanks @KinGP5471.
 - Auto-reply/Compaction: resolve `memory/YYYY-MM-DD.md` placeholders with timezone-aware runtime dates and append a `Current time:` line to memory-flush turns, preventing wrong-year memory filenames without making the system prompt time-variant. (#17603, #17633) Thanks @nicholaspapadam-wq and @vignesh07.
 - Auth/Cooldowns: auto-expire stale auth profile cooldowns when `cooldownUntil` or `disabledUntil` timestamps have passed, and reset `errorCount` so the next transient failure does not immediately escalate to a disproportionately long cooldown. Handles `cooldownUntil` and `disabledUntil` independently. (#3604) Thanks @nabbilkhan.