fix(zcode): recognize current Z.ai built-in plan provider IDs - #1832

Recognizes current Z.ai built-in plan provider IDs in the ZCode adapter so GLM-5.3 and GLM-5.3-Flash rows price from the existing embedded data instead of reporting $0.00 with missing-pricing warnings.

is_zai_provider in rust/adapters/zcode/src/parser.rs now matches the account:zai- and builtin:zai- families by prefix, covering the reported account:zai-individual-coding-plan and account:zai-start-plan IDs plus variants such as builtin:zai-start-plan without enumerating each plan. Existing exact matches and the unknown-custom-provider guard are unchanged, so opaque provider UUIDs still report zero cost with a missing-pricing warning.

Added prices_current_zai_account_and_builtin_plan_ids regression test pricing both GLM models across the three observed plan ID shapes.

Tests: cargo test -p ccusage-adapter-zcode (20 passed), cargo test -p ccusage-adapter-all -- zcode (2 passed), cargo fmt --check and cargo clippy -p ccusage-adapter-zcode -- -D warnings clean.

Out of scope per the issue: BigModel account: plan equivalents and OpenRouter/OpenCode-Go provider mappings were not added since their IDs and usage record shapes are unverified.

Changes left uncommitted in the working tree as instructed.

Closes #1831

Summary by cubic

Fixes the ZCode adapter so current Z.ai built-in plan provider IDs are recognized, pricing GLM-5.3 and GLM-5.3-Flash rows from the embedded data instead of $0.00 with missing-pricing warnings.

• is_zai_provider now matches account:zai- and builtin:zai- provider ID prefixes instead of enumerating each plan, covering account:zai-individual-coding-plan, account:zai-start-plan, and builtin:zai-start-plan plus variants.
• Existing exact matches and the unknown-custom-provider guard are unchanged, so opaque provider UUIDs still report zero cost with a warning.
• Added a regression test pricing both GLM models across the three observed plan ID shapes.

^{Written for commit 210bf3d. Summary will update on new commits.}