fix(pricing): add October catalog display prices

[sandexzx]

Problem

Four models advertised by /provider/v1/models were absent from MODEL_COSTS, so index.ts fell back to ZERO_MODEL_COST and pi displayed no request cost for them (the powerline footer hides the cost segment when it is zero). The clearest symptom: DeepSeek V4.1 Flash Fast (CC) showed no cost at all.

• deepseek/deepseek-v4.1-flash-fast
• claude-sonnet-5-5
• gpt-6.1-sol
• inclusionai/ling-3.1-flash:free

Root cause

The automated catalog syncs (#126, #128) add model metadata to src/commandcode-catalog.ts, but pricing is intentionally manual. deepseek/deepseek-v4.1-flash-fast was added to the catalog by #126 without a matching src/pricing.ts entry. The pricing test only compares MODEL_COSTS against a local fixture, so the drift stayed green.

Changes

• Add reviewed prices from https://commandcode.ai/docs/resources/pricing-limits:
  • claude-sonnet-5-5: 2 / 10 / 0.2 / 2.5
  • gpt-6.1-sol: 2 / 10 / 0.1 / 2.5, tier above 272K 4 / 15 / 0.2 / 5
  • deepseek/deepseek-v4.1-flash-fast: off-peak 0.16 / 0.58 / 0.016 / 0
  • inclusionai/ling-3.1-flash:free: free
• Add deepseek/deepseek-v4.1-flash-fast to DEEPSEEK_V4_TIME_PRICED_MODELS; the pricing page gives it the same weekday 01–04/06–10 UTC peak window (×2), matching deepseek-v4.1-flash.
• Bump PRICING_LAST_VERIFIED to 2026-10-05 and refresh both fixtures (85 models).
• Update the pricing/cost tests and the Unreleased changelog.

Tests

• npm run test:pricing, npm run test:cost, npm run test:models, npm run test:unit, npm run typecheck, npm run format:check, git diff --check — pass.
• npm test passes functionally. Note: tests/test-pi-local.mjs has a pre-existing flaky teardown (Unknown/ENOTEMPTY when removing the temporary HOME, line 1205) that fails intermittently independently of this change; reruns can exit 0. Happy to file a separate issue if useful.

[pierreraby]

Verified: all four prices match the official page (https://commandcode.ai/docs/resources/pricing-limits) read independently just now — v4.1-flash-fast 0.16/0.58/0.016 off-peak (+ time-priced set), Sonnet 5.5 2/10/0.2/2.5, GPT-6.1 Sol 2/10/0.1/2.5 with the 272K tier, Ling 3.1 Flash free. Local on 755e031: typecheck, test-pricing 9/9, test-cost 9/9, test-models 28/28, prettier clean. Leaving the merge to the maintainers — will merge tomorrow if no objections.

[pierreraby]

Re-verified after the author's rebase onto 13acd52 (merge 7039a85, changelog + 0.7.4 version only — no functional change vs 755e031): prices still 4/4 vs the official page, typecheck + test-pricing 9/9 + test-cost 9/9 + test-models 28/28 green locally. Runs approved, merging as announced.

[pierreraby]

Pushed a CHANGELOG conflict resolution onto your branch (0.7.5 released since your rebase — kept both sections, no content change). CI should restart on the new head.

[pierreraby]

Correction to my previous comment: your branch lives on your fork, which I can't push to — so no CI restart happened there. Instead I carried your change forward as #139 (identical content, CHANGELOG conflict with 0.7.5 resolved, verified green locally). The stray upstream ref I created by mistake is deleted. Sorry for the confusion — and thanks again for the PR.