Refresh generated reference app from current DFT

[iphipps]

Purpose

Regenerates the complete discounts reference app from the current DFT source and consolidates the generated sync from #76 with the later intent-parity refresh into one commit on current main.

The generated output comes from merged DFT commit 57e328b8. The rebased commit preserves the exact tree from the previously validated #80 head; only its history and base changed.

This PR supersedes #76. #76 remains open for its owner to close.

Generated changes

• preserves the Add shopify/Discount app intent link snippets for React Router tutorial #75/Resolve discount app intents after save or cancel #78 intent completion, cancellation, App Bridge typing, Sidekick summary, and missing-ID behavior now sourced from DFT
• adds the generated README note directing Shopify employees to DFT
• adds the generated Discounts in Rollouts setup document
• refreshes dependencies and the full example/source drift accumulated since Sync latest discount function examples #76's August 5 generation

The output is committed as generated; it was not manually curated in this repository.

History

• rebased onto current main
• squashed to one commit: Sync latest discount function examples
• final tree is byte-for-byte identical to the previously validated Refresh generated reference app from current DFT #80 head 0109d492

Validation

• full generation completed from DFT 57e328b8
• a second generation from the same source left the worktree clean
• React Router lint passed with 0 errors and 16 existing warnings
• React Router client and SSR builds passed
• mock HTTP server client and SSR builds passed
• default JavaScript Function tests passed (7/7)
• DFT source validation passed before generation: full test suite, type-check, lint, seven Shopify Function CLI smoke cases, and all 132 CodeRef contract entries
• git diff --check

Local generated Rust test/build execution was blocked by host disk pressure (SIGKILL with 1.9 GB free). The corresponding DFT source extension suites passed before generation; CI remains the authoritative generated-output check.