Release 2.0.0: Solo and Team workflows

[patrickschiller]

Summary

Prepare OpenClockwork 2.0.0 as a complete Solo/Team product-generation release.
Existing 1.4.0 installations retain their data and remain in Team mode; Solo is
an explicit installation mode, not a replacement of the existing application.

• Add the complete personal workflow: owner bootstrap/setup, timer and atomic
  project switching, manual entries, correction/cancellation/split history,
  calendar, effective-dated policies and optional personal accounts/hints.
• Add customers, internal/customer projects, service orders, billable time and
  precise gross/break/net reports, privacy-aware CSV and printable statements.
• Protect mode transitions, active-owner boundaries, concurrent revisions,
  current-role/session authorization and the last active administrator.
• Add five forward migrations and strengthen the existing-data upgrade smoke
  assertions without changing previously merged migrations.
• Require explicit disposable database targets and confirmations before E2E,
  seed or reset operations. Remove automatic development startup seeding.
• Align all release metadata and generated API types with 2.0.0. Publish only
  the current curated release-note section, followed by GitHub's changelog.
• Expand README, release notes, upgrade/backup guidance and dedicated Solo,
  Team and operating-mode comparison documentation.

Validation

• 32 API E2E suites / 218 tests passed in a newly isolated disposable database.
• Shared domain: 88 tests passed; web: 27 files / 160 tests passed.
• Release-tooling and database-target safety: 20 tests passed, including
  non-connecting negative CLI tests.
• Workspace lint, typecheck and builds passed; release metadata verified.
• Both 2.0.0 Docker images built and started in separate temporary smoke
  containers; both healthy, web HTTP 200 and proxied API version 2.0.0.
• Azure Bicep reference template compiled locally without a cloud deployment.
• Earlier isolated Docker upgrade/restore and representative browser checks
  cover time boundaries, capture-group breaks, history and report privacy.
  User-supplied print-to-PDF output was visually checked. This does not claim
  universal device/browser certification or a long-running production pilot;
  password/session and mode-transition edge cases also have automated coverage.
• Private local plans, acceptance records, attached PDF, backups, credentials
  and machine-specific addresses are excluded from this PR and image context.

Release and operations

Merge only after CI and DCO are green. Tag the green main merge commit as
v2.0.0; the release workflow verifies it, publishes matching API/web images and
creates the GitHub Release with curated notes.

Production rollout is a separate operator action: retain volumes/timezone,
pause writers, make an encrypted off-machine backup and verify a separate
restore target. No production database is created, reset or migrated by this PR.
Legacy generic-name demo reset scripts intentionally fail closed until their
disposable environment is reviewed. Invoice generation and CAUR agent-usage
accounting remain out of scope.