✨ feat: align syntax, intent clauses, and hole reports

[zrr1999]

Summary

• Align the parser, formatter, type checker, stdlib, examples, and docs with the current Spore surface: inline generic bounds, uses, budget, properties, Str, and intentional rejection of legacy where / cost [...] / spec {} forms.
• Add realization-shape budget checking plus property/budget context projection for typed holes, and surface that context through diagnostics, the LSP, and the new spore explain CLI.
• Update project resolution, scaffold output, README, ROADMAP, and docs/decisions/syntax.md so the implementation repo matches the latest spore-evolution design.
• Keep the earlier cleanup already on this branch: expanded typechecker coverage, hardened recursive source discovery, and separated CLI warning/test internals.

Validation

• cargo fmt --all -- --check
• cargo clippy --all-targets -- -D warnings
• cargo test --all
• cargo run --quiet --bin spore -- check stdlib
• cargo run --quiet --bin spore -- test stdlib
• prek run --all-files

Notes

• This branch reuses PR ✨ feat: align syntax, intent clauses, and hole reports #152, so the title/body now reflect the broader syntax-and-intent alignment work on top of the earlier CLI/source-discovery cleanup.
• Legacy source forms now remain only in intentionally rejected parser/typechecker tests and in docs/decisions/syntax.md.
• No separate planning/audit artifact is included in this PR history.