refactor(db): migrate AI interaction history

Move append-only AI results into an additive provider-aware migration. Preserve generated content, usage counters, indexes, and application cascade semantics.

docs/audits/audit-remediation-backlog.md

@@ -558,7 +558,7 @@ SEC-008 implements the same durable state machine with `<final>.uploading` and `
 
 ### P3-1 — Reduce dual schema ownership incrementally
 
-**Status (2026-08-30): in progress.** All 49 model tables now have an executable, disjoint creation-owner classification. Sixteen formerly reconciler-created tables—including authentication support, email-provider connections, CV extraction persistence, tailored CV drafts, job-workspace AI notes, and CV variant history—have moved through additive provider-aware migrations with legacy-row preservation, downgrade/retry safety, startup-DDL removal, fresh SQLite runtime proof and generated MariaDB SQL. The Gmail decision migration also closes its missing MariaDB creation path. Nineteen startup-created tables remain; see `docs/verification/jt-019-schema-ownership.md` and V-194–V-202.
+**Status (2026-08-30): in progress.** All 49 model tables now have an executable, disjoint creation-owner classification. Seventeen formerly reconciler-created tables—including authentication support, email-provider connections, CV extraction persistence, tailored CV drafts, job-workspace AI notes, CV variant history, and append-only AI interactions—have moved through additive provider-aware migrations with legacy-row preservation, downgrade/retry safety, startup-DDL removal, fresh SQLite runtime proof and generated MariaDB SQL. The Gmail decision migration also closes its missing MariaDB creation path. Eighteen startup-created tables remain; see `docs/verification/jt-019-schema-ownership.md` and V-194–V-203.
 
 - **Findings/scope:** JT-019; inventory reconciler operations and move stable schema ownership to EF migrations in small steps.
 - **Dependencies:** provider upgrade fixtures and P2-2 restore safety.

docs/audits/verification-log.md

@@ -234,3 +234,4 @@ Output was reduced to filenames and commit counts. The token artifact appears un
 | V-200 | Ownership/migration chain; populated adoption/downgrade/retry; FK/index assertions; MariaDB script; full backend | Repository root / disposable local SQLite | Move job-specific tailored CV drafts to migration ownership without losing generated or edited content | PASS — focused ownership/migration 12/12; summary, custom-section and context data survive adoption, downgrade and re-upgrade; both indexes exist; deleting the parent application cascades to the draft; generated MariaDB SQL is provider-safe; startup no longer creates the table; full backend 728/728 | MariaDB SQL generated only; no provider account or production migration. Guarded MariaDB index/auto-increment repairs remain temporarily. Twenty-three reconciler-owned tables remain | JT-019 tailored CV transfer complete; career-profile aggregate remains a dependency-aware future batch |
 | V-201 | Ownership/migration chain; populated adoption/downgrade/retry; FK/index assertions; MariaDB script; full backend | Repository root / disposable local SQLite | Move persisted interview-preparation and irregular AI workspace notes to migration ownership without losing reviewed outputs | PASS — focused ownership/migration 13/13; interview summary and candidate-fit JSON survive adoption, downgrade and re-upgrade; both uniqueness indexes exist; deleting the parent application cascades through both tables; generated MariaDB SQL is provider-safe; startup creates neither table; full backend 729/729 | MariaDB SQL generated only; no provider account or production migration. Guarded MariaDB index/auto-increment repairs remain temporarily. Twenty-one reconciler-owned tables remain | JT-019 job-workspace note transfer complete; CV variants and career-profile aggregates remain dependency-aware batches |
 | V-202 | Ownership/migration chain; populated adoption/downgrade/retry; relationship/index assertions; MariaDB script; full backend | Repository root / disposable local SQLite | Move saved CV variants and append-only revision history to migration ownership without losing user documents | PASS — focused ownership/migration 14/14; public slug, settings and two revisions survive adoption, downgrade and re-upgrade; four indexes exist; deleting the job nulls only the CV link and deleting the CV cascades through revisions; generated MariaDB SQL is provider-safe; startup creates neither table; full backend 730/730 | MariaDB SQL generated only; no provider account or production migration. Guarded malformed-empty/index/auto-increment repair remains temporarily. Nineteen reconciler-owned tables remain | JT-019 CV variant aggregate transfer complete; career-profile aggregate and remaining feature tables continue incrementally |
+| V-203 | Ownership/migration chain; populated adoption/downgrade/retry; usage/FK/index assertions; MariaDB script; full backend | Repository root / disposable local SQLite | Move append-only AI interaction history to explicit migration ownership without losing generated results or usage data | PASS — focused ownership/migration 15/15; result JSON, mode, provider and usage counters survive adoption, downgrade and re-upgrade; both indexes exist; deleting the parent application cascades through history; generated MariaDB SQL is provider-safe; startup no longer creates the table; full backend 731/731 | MariaDB SQL generated only; no provider account or production migration. Historical compatibility bootstrap and guarded counter/shape/index repairs remain. Eighteen reconciler-owned tables remain | JT-019 AI interaction transfer complete; checklist/document/preparation tables continue incrementally |

docs/infrastructure/database-ownership.md

@@ -66,7 +66,8 @@ already-correct database. Two consequences worth knowing:
 
 Created by EF migrations, never by the reconciler:
 
-`AccountDeletionFiles`, `AccountDeletionRequests`, `AiUsageRecords`, `AiWorkspaceNotes`, `Attachments`, `Companies`,
+`AccountDeletionFiles`, `AccountDeletionRequests`, `AiInteractions`, `AiUsageRecords`, `AiWorkspaceNotes`,
+`Attachments`, `Companies`,
 `Correspondences`, `CvExtractionRuns`, `CvUploadArtifacts`, `CvVariants`, `CvVariantVersions`,
 `EmailDrafts`, `EmailSendAttempts`, `GmailConnections`,
 `GmailReviewDecisions`, `ImapConnections`, `InterviewPrepNotes`, `JobApplications`, `JobEvents`, `Jobs`,
@@ -110,6 +111,10 @@ The CV builder aggregate (`CvVariants` and `CvVariantVersions`) moved in
 `20260830128000_AdoptCvVariantSchema`. Public slugs remain unique, deleting a linked application
 sets the CV link to null, and deleting a CV cascades through its append-only revision history.
 
+`AiInteractions` moved in `20260830129000_AdoptAiInteractionSchema`. The older cross-feature usage
+migration retains its compatibility bootstrap for historical chain traversal, but startup no longer
+creates the table; only additive counter and guarded MariaDB shape/index repairs remain.
+
 The reconciler may **repair** these (add a missing column, add an index, fix a non-`AUTO_INCREMENT`
 primary key) and may seed the default `RuleSettings` row — but it must never `CREATE TABLE` them.
 It used to create `RuleSettings`, which is precisely why a clean install failed with
@@ -121,12 +126,14 @@ Created by `StartupInitializationExtensions`, with a **no-op migration** holding
 
 `CareerProfiles`, `CareerProfileVersions`, the six CareerProfile children (`CareerExperiences`,
 `CareerEducations`, `CareerSkills`, `CareerProjects`, `CareerCertifications`, `CareerLanguages`),
-`AiInteractions`, `ApplicationChecklistItems`, `CoverLetterVersions`, and `InterviewPrepItems`.
+`ApplicationChecklistItems`, `CoverLetterVersions`, and `InterviewPrepItems`.
 
 The seven ASP.NET Identity tables are also currently reconciler-owned, despite older wording that
 called them migration-owned: `AspNetRoles`, `AspNetUsers`, `AspNetRoleClaims`, `AspNetUserClaims`,
 `AspNetUserLogins`, `AspNetUserRoles`, and `AspNetUserTokens`. Guarded migration bootstraps for
-`AspNetUsers` and `AiInteractions` support standalone traversal but do not yet transfer ownership.
+`AspNetUsers` supports standalone traversal but does not yet transfer ownership. The historical
+`AiInteractions` bootstrap remains in the migration chain, but its current owner is the later
+provider-aware adoption migration.
 
 `StartupSchemaOwnership` is the executable inventory. Its tests require every EF model table to
 have exactly one creation owner and keep compatibility bootstraps out of the migration-owned set.
@@ -137,7 +144,7 @@ No-op migrations, each with a comment explaining why:
 |---|---|
 | `20260717222917_AddCareerProfileRelationalChildren` | the six CareerProfile children |
 | `20260718074509_AddCvVariants` | historical no-op; ownership transferred by `20260830128000_AdoptCvVariantSchema` |
-| `20260718131138_AddAiInteractions` | `AiInteractions` |
+| `20260718131138_AddAiInteractions` | historical no-op; ownership transferred by `20260830129000_AdoptAiInteractionSchema` |
 | `20260719085904_AddApplicationChecklistItems` | `ApplicationChecklistItems` |
 | `20260719094728_SyncCareerChildKeyLengths` | snapshot sync only |
 | `20260719120954_AddCoverLetterVersions` | `CoverLetterVersions` |

docs/verification/jt-019-schema-ownership.md

@@ -33,6 +33,8 @@ cohesive table groups. It does not attempt to delete the legacy reconciler whole
   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.
 - Corrected the ownership runbook: new tables now default to migrations; the reconciler is legacy
   compatibility code to retire one dependency group at a time.
 
@@ -64,14 +66,16 @@ migration.
   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.
 - Generated MariaDB SQL contains the provider-correct `SystemEmailSettings` DDL.
-- Full backend: 730/730 passed after the CV variant and history transfer.
+- Full backend: 731/731 passed after the AI interaction history transfer.
 - Fresh application startup over a new disposable SQLite database applied
   `20260830120000_AdoptSystemEmailSettingsSchema` and reached the healthy listening state.
 
 ## Remaining JT-019 work
 
-Nineteen model tables remain startup-created, including the Identity group and several tables
+Eighteen model tables remain startup-created, including the Identity group and several tables
 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.

docs/work-programmes/master-progress.md

@@ -52,6 +52,7 @@ Updated: 2026-08-30
 - Moved job-specific tailored CV drafts into a provider-aware migration; generated and edited content, indexes, and application cascade semantics are preserved.
 - Moved persisted interview-preparation and AI workspace notes into one provider-aware migration; reviewed outputs, uniqueness, and application cascades are preserved.
 - Moved saved CV variants and append-only revision history into one provider-aware migration; public slugs, settings, indexes, job-link nulling, and history cascades are preserved.
+- Moved append-only AI interaction history into a provider-aware migration; generated results, modes, providers, usage counters, indexes, and application cascades are preserved.
 
 ### In progress
 
@@ -82,7 +83,7 @@ Updated: 2026-08-30
 - Focused frontend: 2 suites, 6 tests passed.
 - Full frontend: 64 suites, 272 tests passed.
 - Next production build and TypeScript: passed.
-- Full backend: 730/730 tests passed after the CV variant/history JT-019 transfer.
+- Full backend: 731/731 tests passed after the AI interaction history JT-019 transfer.
 - Portable Playwright launcher: resolved the user-local .NET 9 SDK; backend Release build passed with 0 warnings/errors.
 - Playwright: initial full run 9/10 exposed the intentional mobile Settings control change; updated focused rerun passed 1/1. A final complete browser rerun remains in the end-of-batch gate.
 - Focused backend match/intelligence verification: 34/34 passed.