Align private review pricing with the approved euro tiers

Chris explicitly reconfirmed EUR 29.99/month for LSU Running + Strength. The private roles/plans/demo guides and scripts/lsu-demo-plan.ts still show USD 29. HQ's launch preset and real sandbox acceptance already use the approved EUR 29.99.

Align the demo tier, seed description and guides with tax-inclusive EUR 29.99/month. Mention the approved EUR 19.99 running tier where launch pricing is described. Preserve complimentary review access, workouts, roles and all genuine purchase terms. Refuse any attempt to rewrite provider-backed or purchased subscriptions when aligning old complimentary fixture metadata.

Observed guide: https://lsu.stacksjs.com/docs/roles Related: https://github.com/stacksjs/hq.training/issues/346, https://github.com/stacksjs/hq.training/issues/353 and https://github.com/stacksjs/hq.training/commit/778c4eaa4.

Implemented in https://github.com/stacksjs/lastsoulultra/commit/996c02c. The review offer and existing guarded seeder now use EUR 29.99, and the guide documents EUR 19.99 Running / EUR 29.99 Running + Strength, tax included, with shares after tax. Checks: 211 tests pass using the exact Bun 1.4.4 pin; lint/typecheck, docs build and the 23-page docs audit pass. Normal CI/deploy is running; production readback remains to be verified.

Production readback verified: the roles and plans guides return HTTP 200 with EUR 29.99 and tax-inclusive wording, the plans page includes EUR 19.99 Running and shares after tax, and the retired USD 29 copy is absent. Unauthenticated requests still return HTTP 401. The guarded source seeder updated the same production demo offer to EUR 2999 cents while retaining both complimentary subscribers, existing passwords and edited training; zero provider-backed subscriptions. Normal CI and deploy succeeded: https://github.com/stacksjs/lastsoulultra/actions/runs/40870108070 and https://github.com/stacksjs/lastsoulultra/actions/runs/40870193347 .