docs: name gpt-6.1-sol and gpt-6-luna as the current Codex tiers (#2943)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

changelog.d/gsta214-a.md

@@ -0,0 +1,9 @@
+**Eval planning prices Claude Haiku 5.5, GPT-6 Luna and Gemini 4 Argon, and the Codex docs name the current OpenAI tiers (#3640, #2943).** Before, `gstack-eval-plan arms --arms claude-haiku-5-5` stopped with EVAL_PRICE_MISSING because `lib/pricing.ts` had no row for it. docs/hosts.md and the /codex example still named gpt-5.6-sol as the current Sol model.
+
+### Added
+- **Price rows** for `claude-haiku-5-5` ($0.10 / $0.50, cached $0.01, standard tier up to 100,000 tokens), `gpt-6-luna` ($0.10 / $0.50, cached $0.01) and `gemini-4-argon` ($4.00 / $20.00, cached $0.20). Each row cites its provider page. Argon uses the rates that start on 2026-12-01, so estimates never come in low after that date. A repository's model-policy document that names one of these models now gets it as an eval arm.
+
+### Changed
+- **docs/hosts.md and /codex** name `gpt-6-astra`, `gpt-6.1-sol` and `gpt-6-luna` as the current tiers. They also say the bounded-scope overlay still applies only to `gpt-5.6-sol` until it has its own eval.
+
+Thanks to @exGeni (#3640) and @DanCanadian (#2943) for the reports. The TypeSafe Jev rows from #3640 are not included, because a $0 output price breaks the price table's rule that every row has an output price.

codex/SKILL.md

@@ -550,7 +550,7 @@ codex >=0.144), the `-c` form explicitly overrides any top-level
 web search regardless of configuration, so on the default Review path the flag is a
 harmless no-op — only exec-based modes actually search.
 
-If the user specifies a model (e.g., `/codex review -m gpt-5.6-sol` or
+If the user specifies a model (e.g., `/codex review -m gpt-6.1-sol` or
 `/codex challenge --model gpt-daybreak-blue-latest`), translate it to the same config
 form and replace the default model flag with `-c "model=\"<model>\""`. Native review
 also requires `-c "review_model=\"<model>\""`; replace both model values together.

codex/SKILL.md.tmpl

@@ -271,7 +271,7 @@ codex >=0.144), the `-c` form explicitly overrides any top-level
 web search regardless of configuration, so on the default Review path the flag is a
 harmless no-op — only exec-based modes actually search.
 
-If the user specifies a model (e.g., `/codex review -m gpt-5.6-sol` or
+If the user specifies a model (e.g., `/codex review -m gpt-6.1-sol` or
 `/codex challenge --model gpt-daybreak-blue-latest`), translate it to the same config
 form and replace the default model flag with `-c "model=\"<model>\""`. Native review
 also requires `-c "review_model=\"<model>\""`; replace both model values together.

docs/hosts.md

@@ -154,11 +154,14 @@ digest's first line shows its gstack version; re-copy it after upgrading.
 For Codex, setup reads the top-level `model` from
 `${CODEX_HOME:-~/.codex}/config.toml` and generates the matching behavioral
 profile, falling back to `gpt-6-astra` when no usable model is configured.
-`gpt-5.6-sol` automatically receives bounded-scope instructions that
-finish the requested lake without expanding into adjacent cleanup or speculative
-hardening. The Sol profile is exact-match only: dated snapshots and other 5.6
-variants get the generic GPT profile, and setup warns on near-misses like
-`gpt-5.6-sol-2026-08-01`. Override detection with `./setup --host codex --model <id>` — the
+The current OpenAI tiers are `gpt-6-astra` (frontier), `gpt-6.1-sol` (smart, the
+default eval and outside-voice tier) and `gpt-6-luna` (lowest cost); `gpt-6.1-sol`
+and `gpt-6-luna` get the generic GPT profile. Only `gpt-5.6-sol` receives the
+bounded-scope instructions that finish the requested lake without expanding into
+adjacent cleanup or speculative hardening, because that patch was measured on 5.6
+Sol; extending it to `gpt-6.1-sol` waits for its own scope eval. The Sol profile is
+exact-match only: dated snapshots and other 5.6 variants get the generic GPT
+profile, and setup warns on near-misses like `gpt-5.6-sol-2026-08-01`. Override detection with `./setup --host codex --model <id>` — the
 override applies to that run only; set `model` in your Codex `config.toml` to
 make it stick across upgrades. After changing your Codex model, rerun
 `./setup --host codex` to regenerate the skills.