> For the complete documentation index, see [llms.txt](https://ai-os-and-trend-finder.gitbook.io/ai-os-and-trend-finder-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ai-os-and-trend-finder.gitbook.io/ai-os-and-trend-finder-docs/.spec_system/archive/sessions/phase27-session04-daily-time-series-persistence-and-sparklines/implementation_summary.md). # Implementation Summary **Session ID**: `phase27-session04-daily-time-series-persistence-and-sparklines` **Completed**: 2026-06-12 **Duration**: 1.3 hours *** ## Overview Session 04 completed the first Tier 2 Alpha Radar adoption foundation for Trend Finder by adding private daily topic-series persistence, bounded browser-safe sparklines, and Hugging Face model download delta context. The runtime now records canonical topic daily evidence counts and public model download observations in private snapshots, assembles 14-day sparkline projections, and shows explicit missing-history or no-baseline states instead of inferred precision. The work kept snapshot archives private, preserved legacy payload and snapshot compatibility through additive defaults, and reused projected view models for card and Signal Workbench rendering. *** ## Deliverables ### Files Created | File | Purpose | Lines | | ------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | ----- | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/spec.md` | Session scope and implementation contract. | 382 | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/tasks.md` | 20-task checklist and completion tracker. | 94 | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/implementation-notes.md` | Task-by-task implementation record. | 488 | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/security-compliance.md` | Security and GDPR review. | 89 | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/validation.md` | Validation report and quality gates. | 259 | | `scripts/lib/ai-runtime/trend-series.ts` | Pure daily bucket, sparkline, and Hugging Face download delta helpers. | 407 | | `scripts/lib/ai-runtime/__tests__/trend-series.test.ts` | Unit tests for UTC buckets, bounds, zero-fill, deltas, no-baseline, and malformed dates. | 152 | | `src/extensions/trend-finder/components/trend-sparkline.tsx` | Reusable compact SVG sparkline with stable dimensions and accessible labels. | 56 | | `src/extensions/trend-finder/components/__tests__/trend-sparkline.test.tsx` | Component and table tests for sparkline rendering, empty states, and labels. | 68 | | `.spec_system/specs/phase27-session04-daily-time-series-persistence-and-sparklines/IMPLEMENTATION_SUMMARY.md` | Session closeout summary. | 138 | ### Files Modified | File | Changes | | ---------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | | `.spec_system/PRD/phase_27/PRD_phase_27.md` | Marked Session 04 complete, updated progress to 4/12, recorded completion details, and advanced upcoming work to Session 05. | | `.spec_system/state.json` | Added Session 04 to completed sessions and history; cleared current session. | | `package.json` | Bumped patch version from 0.1.306 to 0.1.307. | | `README.md` | Updated the displayed project version to 0.1.307. | | `scripts/lib/ai-runtime/snapshots.ts` | Added optional private series branches, legacy defaults, validation, and write typing for snapshot read/write compatibility. | | `scripts/lib/ai-runtime/historical-context.ts` | Added bounded topic sparkline context, model download baseline lookup, missing-history states, and future snapshot exclusion. | | `scripts/extensions/trend-finder/collector.ts` | Built current-run daily counts, attached topic sparklines and Hugging Face download deltas, emitted bounded warnings, and persisted private series data. | | `src/extensions/trend-finder/schema.ts` | Added capped topic sparkline and evidence download delta schemas with additive defaults and strict browser bounds. | | `src/extensions/trend-finder/view-model.ts` | Added sparkline projections, SVG coordinate strings, accessible labels, Workbench fields, and download delta chip labels. | | `src/extensions/trend-finder/components/trend-card.tsx` | Rendered daily signal sparklines and explicit unavailable copy on trend cards. | | `src/extensions/trend-finder/signal-workbench-model.ts` | Added sparkline row fields, facets, filtering, deterministic sort keys, and Hugging Face delta evidence labels. | | `src/extensions/trend-finder/components/signal-workbench-table.tsx` | Rendered a fixed Trend sparkline column and Hugging Face download delta pills in evidence rows. | | `src/extensions/trend-finder/fixtures.ts` | Added sparkline, missing-history, Hugging Face delta, no-baseline, and source summary fixture coverage. | | `scripts/lib/ai-runtime/__tests__/snapshots.test.ts` | Covered private series persistence and legacy snapshot defaults. | | `scripts/lib/ai-runtime/__tests__/historical-context.test.ts` | Covered bounded sparkline assembly, model baselines, future snapshot exclusion, and missing-history states. | | `src/lib/__tests__/trend-finder-schema.test.ts` | Covered schema defaults, bounds, private-field fallback, and download delta parsing. | | `src/lib/__tests__/trend-finder-dashboard.test.tsx` | Covered sparkline view-model projection and Hugging Face delta chip labels. | | `src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts` | Covered sparkline filtering, facets, and deterministic ordering. | | `src/extensions/trend-finder/__tests__/visibility-views.test.tsx` | Derived source-count assertions from fixture data after adding the Hugging Face source summary. | *** ## Technical Decisions 1. **Private series boundary**: Daily topic counts and model download observations are persisted only in snapshot `series` branches, while the browser receives capped sparkline and delta projections. 2. **Additive compatibility**: Snapshot and browser schemas use optional branches and defaults so legacy snapshots, payloads, and fixtures continue to parse without migration. 3. **Explicit state modeling**: Missing history, first-seen models, missing or invalid counts, and decreased downloads render as intentional states rather than guessed growth metrics. 4. **Projected rendering**: Cards and Workbench rows consume view-model sparkline and delta labels instead of deriving private runtime semantics in React components. *** ## Test Results | Metric | Value | | -------- | ------- | | Tests | 3362 | | Passed | 3362 | | Coverage | Not run | Commands validated: * `bun run typecheck` - passed. * `bun run typecheck:scripts` - passed. * Focused Trend Finder tests - passed, 7 files / 151 tests. * `bun run test` - passed, 271 files / 3362 tests. * `bun run lint` - passed with 3 existing warnings outside session deliverables. * `bun run build` - passed. * `bun run budget:check` - passed, 0 violations. * `bunx prettier --check [session deliverables + validation-time test fix]` - passed. * `git diff --check` - passed. * Modified/untracked ASCII validation - passed. *** ## Lessons Learned 1. Daily series become safest when the private snapshot contract and browser projection are modeled as separate additive shapes. 2. Download deltas need first-seen, missing, invalid, and decreased states to avoid turning sparse public metrics into false precision. 3. Dense sparkline UI should be projected through shared view models so cards and Workbench tables keep stable sizing and accessible labels. *** ## Future Considerations Items for future sessions: 1. Session 05 can compute velocity, acceleration, significance, and burst from the private daily series without widening the browser contract. 2. Session 07 can reuse the same historical context layer for convergence and trajectory visuals. 3. A future SQLite observation store can replace snapshot-file derivation while keeping the 14-day browser projection stable. *** ## Session Statistics * **Tasks**: 20 completed * **Files Created**: 10 * **Files Modified**: 19 * **Tests Added**: 7 test files added or updated * **Blockers**: 0 resolved --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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