[P1][SDK] Align PHP package metadata and quickstarts with canonical product facts

[karlwaldman]

Outcome

Remove discoverable contradictions from the PHP SDK and publish one tested installation/auth/first-request path aligned with the reviewed public product-facts contract.

Scope

Audit the GitHub description, README, Composer metadata, Packagist text, examples, release notes, docs links, badges, and code comments that make product-level claims.

Acceptance Criteria

• Package/install name, minimum supported PHP version, API base URL, auth behavior, environment convention, and first request are verified from executable code.
• Examples use versioned routes and current commodity codes and cover 401/403/429 recovery.
• No unsupported fixed refresh cadence, universal catalog count/access, WebSocket, SLA, price, history, redistribution, or plan claim remains.
• Mutable facts link to the reviewed product contract rather than being duplicated where possible.
• CI installs the built package in a clean environment and runs the exact documented example against fixtures plus a guarded smoke.
• Packagist/GitHub metadata is republished or updated and the public URLs are attached to the issue.
• A drift check flags future high-risk product literals.

Dependencies

• OilpriceAPI/oilpriceapi-api#4799.
• OilpriceAPI/oilpriceapi-docs#104.

[karlwaldman]

Tracked and sequenced in the P1 LLM Source Accuracy sprint: https://github.com/OilpriceAPI/website-clean/issues/1305

[karlwaldman]

Release evidence - PHP SDK v2.1.0

• PR: fix: harden canonical PHP quickstart #8
• Release: https://github.com/OilpriceAPI/oilpriceapi-php/releases/tag/v2.1.0
• Exact source: 27c8c1e225edaf66f5851ff08acfdd5f6af06dc7
• Public tag workflow: https://github.com/OilpriceAPI/oilpriceapi-php/actions/runs/29691312483
• Packagist: https://packagist.org/packages/oilpriceapi/oilpriceapi#v2.1.0

Packagist exposes v2.1.0 with the corrected description/homepage and exact source SHA; a fresh public Composer install reports 2.1.0. Tag CI passed PHP 8.1/8.2/8.3, packaged ZIP install, five quickstart recovery fixtures, claims drift, and the strict live production request. GitHub description, homepage, and topics are corrected. Publication is a distribution receipt, not a citation-uplift claim.