# JT-019 schema ownership — incremental migration transfers

## Scope

This work establishes a behaviour-preserving ownership boundary and moves small independent or
cohesive table groups. It does not attempt to delete the legacy reconciler wholesale.

## Implemented

- Added `StartupSchemaOwnership`, classifying all 49 EF model tables into disjoint migration-owned
  and reconciler-owned creation sets.
- Added a regression that fails when a model table is unclassified, multiply classified, or when a
  compatibility bootstrap is incorrectly treated as migration ownership.
- Added `20260830120000_AdoptSystemEmailSettingsSchema`, with provider-aware additive DDL for SQLite
  and MariaDB/MySQL.
- Removed the MariaDB startup `CREATE TABLE` block for `SystemEmailSettings` and moved the table to
  the migration-owned set.
- Added `20260830121000_AdoptUserRuleSettingsSchema` and removed both provider startup-create paths
  for the independent per-user rule-settings table.
- Added `20260830122000_AdoptGmailReviewDecisionsSchema`, removed the SQLite startup-create path,
  and supplied the previously absent MariaDB table definition.
- Added `20260830123000_AdoptAuthenticationSupportSchema` for recovery codes, trusted devices, and
  revocable user sessions; both provider startup-create paths are removed while guarded MariaDB
  repair checks remain for historical schemas.
- Added `20260830124000_AdoptEmailConnectionSchema` for Gmail, Microsoft Graph, and IMAP connection
  records. Encrypted credentials and sync state are retained; scoped Gmail column repair and guarded
  MariaDB index/identity repair remain for historical installations.
- Added `20260830125000_AdoptCvExtractionSchema` for upload artifacts and extraction runs, retaining
  parsed output and the nullable `ON DELETE SET NULL` artifact relationship.
- Added `20260830126000_AdoptTailoredCvDraftSchema` for the job-specific tailored document, retaining
  generated and manually edited content plus its `ON DELETE CASCADE` application relationship.
- Added `20260830127000_AdoptJobWorkspaceNotesSchema` for interview preparation and irregular AI
  workspace results, retaining reviewed output and both application cascade relationships.
- Added `20260830128000_AdoptCvVariantSchema` for saved CVs and their append-only revision history,
  retaining public slugs, builder settings, and job-link/version retention semantics.
- Added `20260830129000_AdoptAiInteractionSchema` to take ownership from both the startup reconciler
  and historical compatibility bootstrap while retaining append-only results and usage counters.
- Added `20260830130000_AdoptApplicationChecklistSchema` for application workflow state, retaining
  stable system keys, manual steps, completion state, and user ordering.
- Added `20260830131000_AdoptCoverLetterVersionSchema` for append-only document history, retaining
  manual and AI-approved text plus source/action metadata.
- Added `20260830132000_AdoptInterviewPrepItemSchema` for durable interview-practice content,
  retaining user and AI questions, answers, prepared state, source metadata, and ordering.
- Added `20260830133000_AdoptCareerProfileSchema` for the canonical profile, append-only history,
  and all six ordered relational child types. Legacy JSON, Norwegian text, stable keys, and cascade
  ownership are retained.
- Added `20260830134000_AdoptIdentitySchema` for the complete ASP.NET Identity aggregate, preserving
  accounts, password hashes, 2FA state, preferences, roles, claims, external logins, and tokens.
- Corrected the ownership runbook: new tables now default to migrations; the reconciler is legacy
  compatibility code to retire one dependency group at a time.

## Data compatibility

The migration uses `CREATE TABLE IF NOT EXISTS`. Existing MariaDB installations keep their table and
rows; SQLite installations that never received the reconciler-only table now receive it. `Down` is
intentionally non-destructive because it cannot determine whether the existing table predates this
migration.

## Proof

- Ownership and migration-chain focused suite: 6/6 passed.
- Blank SQLite chain applies all migrations twice and creates all ten expected
  `SystemEmailSettings` columns.
- A database stopped immediately before the adoption migration, seeded with a representative SMTP
  settings row, upgrades without changing that row.
- A representative per-user rules row survives adoption, downgrade, and re-upgrade.
- A representative Gmail review decision survives adoption, downgrade, and re-upgrade.
- Representative recovery-code, trusted-device, and user-session rows survive adoption, downgrade,
  and re-upgrade, and their indexes are present afterwards.
- Representative encrypted credentials for all three email providers survive adoption, downgrade,
  and re-upgrade, and all five expected provider indexes are present afterwards.
- Representative CV artifact metadata and structured extraction output survive adoption, downgrade,
  and re-upgrade; deleting the artifact preserves the run and clears its nullable relationship.
- A representative tailored CV's summary, custom section, and generation context survive adoption,
  downgrade, and re-upgrade; deleting the parent application still deletes its draft.
- Representative interview-preparation and candidate-fit outputs survive adoption, downgrade, and
  re-upgrade; deleting the parent application still deletes both cached note types.
- A representative CV and two saved revisions survive adoption, downgrade, and re-upgrade; deleting
  its job clears only the optional link, while deleting the CV cascades through its revisions.
- A representative AI result, mode, provider, and usage counts survive adoption, downgrade, and
  re-upgrade; deleting the parent application still cascades through its interaction history.
- Representative system-generated and manual checklist steps survive adoption, downgrade, and
  re-upgrade; deleting the parent application still cascades through its workflow items.
- Representative manual and AI cover-letter revisions survive adoption, downgrade, and re-upgrade;
  deleting the parent application still cascades through document history.
- Representative user-authored and AI-generated interview-preparation items survive adoption,
  downgrade, and re-upgrade with practice state intact; their ordering index and application cascade
  remain effective.
- A populated Career Profile with history, long-tail JSON, Norwegian text, experience, education,
  skills, projects, certifications, and languages survives adoption, downgrade, and re-upgrade; all
  14 aggregate indexes and parent cascades remain effective.
- A populated Identity account with password hash, Bokmål preference, 2FA state, role assignment,
  role/user claims, external login, and token survives adoption, downgrade, and re-upgrade; all eight
  Identity indexes and user/role cascades remain effective.
- Generated MariaDB SQL contains the provider-correct `SystemEmailSettings` DDL.
- Full backend: 736/736 passed after the Identity aggregate transfer.
- Fresh application startup over a new disposable SQLite data root applied the complete chain,
  queried/seeded Identity roles, and reached the healthy listening state with no schema failure.
- Fresh application startup over a new disposable SQLite database applied
  `20260830120000_AdoptSystemEmailSettingsSchema` and reached the healthy listening state.

## Remaining JT-019 work

No EF model tables remain startup-created. JT-019's creation-ownership transfer is complete; the
startup reconciler now performs compatibility repair only and can be reduced further when historical
provider fixtures prove individual repairs obsolete.
with parent dependencies. Transfer them in small dependency-aware migrations with blank, populated,
retry and MariaDB runtime proof. Column/index repairs must remain until historical upgrade fixtures
prove each one redundant.
