feat(opencode): port Astra system prompt from v2 - #48057

Upstream v1.18.29 (1674747, merged at 18a4845) -> v1.18.30 (3104c14),
28 commits / 105 files. Staged delta vs pre-merge fork HEAD is identical to
the upstream tag-to-tag diff (105 files, +1676/-403), confirming a clean
adoption.

Functional changes:
- feat(opencode): port Astra system prompt from v2 (anomalyco#48057) — new
  session/prompt/gpt-astra.txt wired through system.ts; fork's system
  transforms live in the openchamber plugin, no overlap.
- fix: preserve Bedrock DeepSeek model ids (anomalyco#34441) — provider.ts Bedrock
  loader passes arn: model ids through unmodified and tightens the
  cross-region prefix match from "deepseek" to "deepseek.r1"; inside the
  custom Azure/Bedrock loader region, disjoint from the fork snapshot
  architecture.
- fix(provider): preserve explicit OpenAI service tiers (anomalyco#47671).
- fix(opencode): add GitLab reasoning variants (anomalyco#47306) — transform.ts
  reasoningEffort now routes gitlab gpt-family to reasoningEffort and
  claude-family to adaptive thinking; disjoint from the fork GLM/ZhiPu
  normalization block, which remains intact (+77 fork-only lines).
- SDK bumps: @ai-sdk/openai 3.0.88, @ai-sdk/azure 3.0.93,
  gitlab-ai-provider 6.15.0 (8 packages installed via bun install).
- console: oauth client metadata document (anomalyco#47737), Chatwoot enterprise
  form (anomalyco#47488), openai usage normalization + tier threshold (anomalyco#47342),
  localized refund FAQs, zen model table updates (muse spark); go.mdx
  client session compatibility docs incl. zh translation.

Conflicts resolved: 29 package.json version bumps (rebranded 1.18.30-sscity
with a version-generic pattern after the v1.18.27 incident), bun.lock (took
upstream, rebranded workspace entries via bun install). Fork deltas
verified intact vs v1.18.30: ProviderSnapshot architecture (+492 in
provider.ts), deferred snapshot init, GLM normalization (+77 in
transform.ts), config getFresh/commitFresh (+14). Tests: provider,
transform, bedrock, config, v2, azure plugin, session retry/llm — 1058
pass / 0 fail across 15 files (22 new upstream tests included); typecheck
clean.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Port upstream opencode 5cd8e68fdd (anomalyco/opencode#48057, user-approved
triage decision #13): the 46-line Astra system prompt for gpt-6-family
models, fetched from the upstream sha via raw (commit is outside the local
mirror window).

Brand rewrite per fork naming rules: the only OpenCode mention (line 1
identity claim) is rewritten to "powered by Chimera, a coding agent
harness"; the remaining 45 lines are brand-neutral and kept verbatim.

Registration follows the fork's data-driven layer table instead of the
upstream if-chain: one SPECIALIZATIONS entry keyed "model/gpt-astra"
(substring key "gpt-6" on the api id), placed before model/codex and
model/gpt so the first-match-wins order mirrors upstream, where the
gpt-6 check precedes both (a codex-namespaced gpt-6 lands on Astra).

Default invariance: "gpt-6" is not a substring of any current model id
(gpt-5.6* verified), so with no gpt-6-family model the assembly is
byte-identical to before. Anchor tests pin both directions: gpt-6 family
-> Astra segment keys/markers, and 11 representative non-gpt-6 ids ->
unchanged segment attribution with zero Astra content.

Upstream-Sha: 5cd8e68fdd