> 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/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md). # Implementation Notes **Session ID**: `phase28-session05-signal-aging-half-lives-and-saturation-refinement` **Started**: 2026-06-14 04:04 **Last Updated**: 2026-06-14 04:35 *** ## Session Progress | Metric | Value | | ------------------- | --------- | | Tasks Completed | 24 / 24 | | Estimated Remaining | 0 minutes | | Blockers | 0 | *** ## Task Log ### 2026-06-14 - Session Start **Environment verified**: * [x] Prerequisites confirmed * [x] Tools available * [x] Directory structure ready *** ### Task T001 - Verify prerequisite sessions, source mapping, and target paths **Started**: 2026-06-14 04:03 **Completed**: 2026-06-14 04:04 **Duration**: 1 minute **Notes**: * Confirmed active session from deterministic project analysis: `phase28-session05-signal-aging-half-lives-and-saturation-refinement`. * Confirmed prerequisite environment checks passed, including Bun 1.3.14. * Confirmed required prior sessions are marked complete in state: Session 03, Session 04, Phase 27 saturation, and Phase 27 lifecycle baseline. * Confirmed Trends-Finderz reference files and all target implementation, UI, fixture, test, and documentation paths exist. **Files Changed**: * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` - Created session progress log. *** ### Task T002 - Create implementation-notes shell **Started**: 2026-06-14 04:04 **Completed**: 2026-06-14 04:04 **Duration**: 1 minute **Notes**: * Created the session notes shell with environment verification, progress metrics, task logging sections, and space for decisions, validation commands, and residual risks. * Established task-by-task logging for scoring-version rationale and deferred non-goals as the session proceeds. **Files Changed**: * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` - Added implementation notes structure. *** ### Task T003 - Compare Trends-Finderz constants to Trend Finder scales **Started**: 2026-06-14 04:04 **Completed**: 2026-06-14 04:05 **Duration**: 1 minute **Notes**: * Reviewed Trends-Finderz signal-aging half-lives: discussion/news decay fast, developer/creator decay slower, and research decays slowest. * Reviewed Trends-Finderz lifecycle freshness thresholds and retained them only as aging calibration fixtures. The Trend Finder lifecycle vocabulary remains `unknown`, `whisper`, `builder`, `creator`, and `saturated`. * Reviewed Trends-Finderz saturation shape and mapped it to Trend Finder's existing source pressure, evidence volume, recurrence, healthy-source denominator, and hidden-gem contracts. * Confirmed saturation stays display-derived in this session and the six-factor opportunity weight table remains unchanged. **Files Changed**: * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` - Recorded calibration comparison. **BQC Fixes**: * Contract alignment: Chose role-level defaults and bounded outputs so the browser payload does not import Trends-Finderz lifecycle labels. *** ## Design Decisions ### Decision 1: Role-level half-lives with calibrated saturation inputs **Context**: Trends-Finderz uses source-name half-lives and a separate lifecycle vocabulary, while Trend Finder already has role metadata, lifecycle fields, and Phase 27 saturation contracts. **Options Considered**: 1. Copy Trends-Finderz source-name constants and lifecycle labels - faster but would create a second lifecycle system and hardcoded source-name coupling. 2. Map half-lives to existing Trend Finder source roles and keep lifecycle labels out of the payload - slightly more calibration work but aligned with the current contract. **Chosen**: Role-level half-life defaults with declaration-level overrides. **Rationale**: This preserves existing source declarations, keeps payloads bounded, avoids lifecycle drift, and allows reviewed source exceptions without adding new adapters or dependencies. *** ### Task T004 - Add source half-life metadata contracts **Started**: 2026-06-14 04:05 **Completed**: 2026-06-14 04:06 **Duration**: 1 minute **Notes**: * Added role-level half-life defaults for developer, discussion, research, launch, creator, and news roles. * Added shared half-life bounds for config validation. * Added optional `halfLifeHours` metadata to source adapter metadata and Apify source config declarations. **Files Changed**: * `scripts/extensions/trend-finder/sources/types.ts` - Added half-life bounds, role defaults, and optional source metadata fields. **BQC Fixes**: * Contract alignment: Added typed role defaults and optional metadata at the source boundary before downstream scoring consumes the field. *** ### Task T005 - Wire source half-life defaults and override validation **Started**: 2026-06-14 04:06 **Completed**: 2026-06-14 04:07 **Duration**: 1 minute **Notes**: * Added `halfLifeHours` and `signalHalfLifeHours` metadata parsing for Apify actor env/file records. * Added integer bound validation using the shared 24-720 hour range. * Defaulted each loaded source to the half-life for its resolved source role when no valid override or declaration value is present. * Added a resolver exported for focused source-config tests. **Files Changed**: * `scripts/extensions/trend-finder/sources/apify-source-config.ts` - Added half-life parsing, validation warnings, role default resolution, and enriched config output. **BQC Fixes**: * Trust boundary enforcement: Env/file metadata is validated before entering source config. * Failure path completeness: Invalid half-life metadata records a bounded field warning and falls back to role defaults. *** ### Task T006 - Create pure signal-aging helper **Started**: 2026-06-14 04:07 **Completed**: 2026-06-14 04:10 **Duration**: 3 minutes **Notes**: * Added a pure `buildSignalAgingProfile()` helper with half-life freshness, status transitions, unavailable states, warning mapping, and bounded source-role contributions. * Added reusable `calculateSignalAgeHours()`, `calculateHalfLifeFreshnessScore()`, and `resolveSignalHalfLifeHours()` utilities for scoring integration. * Kept output role-based and bounded; no raw evidence title, URL, source dump, prompt text, or private path is returned. **Files Changed**: * `scripts/lib/ai-runtime/signal-aging.ts` - Added signal-aging derivation, validation, unavailable profiles, and contribution helpers. **BQC Fixes**: * Trust boundary enforcement: Helper validates input shape and normalizes roles, half-lives, and dates before derivation. * Failure path completeness: Bad input returns explicit unavailable states with warning codes instead of throwing or guessing. * Contract alignment: Output uses bounded enums and role contributions only. *** ### Task T007 - Add signal-aging unit tests **Started**: 2026-06-14 04:10 **Completed**: 2026-06-14 04:11 **Duration**: 1 minute **Notes**: * Added focused Vitest coverage for per-role decay differences, status transitions, unavailable states, contribution limits, invalid metadata warnings, and stale-age lifecycle fixtures. * Confirmed the helper does not emit Trends-Finderz lifecycle labels. **Files Changed**: * `scripts/lib/ai-runtime/__tests__/signal-aging.test.ts` - Added helper unit coverage. **Validation**: * `bunx vitest run scripts/lib/ai-runtime/__tests__/signal-aging.test.ts` passed: 1 file, 5 tests. *** ### Task T008 - Add signal-aging schema defaults **Started**: 2026-06-14 04:11 **Completed**: 2026-06-14 04:13 **Duration**: 2 minutes **Notes**: * Added signal-aging status, contribution status, unavailable reason, and warning-code enums. * Added neutral unavailable defaults for legacy reports. * Added bounded source-role contribution schemas and parsed topic `signalAging` field with catch/default behavior. **Files Changed**: * `src/extensions/trend-finder/schema.ts` - Added signal-aging constants, defaults, schemas, and optional topic type projection. **BQC Fixes**: * Contract alignment: Legacy payloads parse with an unavailable default rather than requiring migration. * Error information boundaries: Browser schema exposes warning codes, not raw exception details or source payloads. *** ### Task T009 - Add signal-aging view-model projection **Started**: 2026-06-14 04:13 **Completed**: 2026-06-14 04:14 **Duration**: 1 minute **Notes**: * Added signal-aging labels, tones, unavailable reason labels, sort ranks, and bounded source-role contribution projection. * Added signal-aging to the existing derived-signals view model alongside saturation, hidden-gem score, quality, visibility, and velocity dynamics. **Files Changed**: * `src/extensions/trend-finder/view-model.ts` - Added signal-aging view-model interfaces, helper functions, and derived-signal wiring. **BQC Fixes**: * Accessibility and platform compliance: Projection emits deterministic aria labels for status and role contributions. * Contract alignment: UI code receives bounded labels and sort ranks instead of raw helper internals. *** ### Task T010 - Refine saturation helper inputs and constants **Started**: 2026-06-14 04:14 **Completed**: 2026-06-14 04:16 **Duration**: 2 minutes **Notes**: * Extended saturation input to typed scoring evidence and bounded topic text. * Preserved null saturation when evidence is empty or no healthy source denominator exists. * Added calibrated diffusion, mention density, mainstream-term pressure, and single-source/developer dominance discount inputs on top of the Phase 27 base. **Files Changed**: * `scripts/lib/ai-runtime/scoring.ts` - Refined saturation inputs and formula. **BQC Fixes**: * Contract alignment: Kept the existing `saturation` field and unavailable contract instead of adding a competing score multiplier or new payload field. *** ### Task T011 - Use half-life recency in momentum scoring **Started**: 2026-06-14 04:16 **Completed**: 2026-06-14 04:17 **Duration**: 1 minute **Notes**: * Added optional `halfLifeHours` to browser-safe source summaries and forwarded it from Apify source configs. * Added a source half-life map to scoring context. * Replaced uniform recency buckets in the momentum component with half-life freshness while retaining the previous invalid-date fallback score. * Left `OPPORTUNITY_SCORE_WEIGHTS` unchanged. **Files Changed**: * `src/extensions/trend-finder/schema.ts` - Added optional source-summary `halfLifeHours`. * `scripts/extensions/trend-finder/sources/apify-adapter.ts` - Forwarded source half-life metadata. * `scripts/lib/ai-runtime/scoring.ts` - Wired half-life recency into momentum. **BQC Fixes**: * Failure path completeness: Invalid recency timestamps continue to use the existing bounded fallback instead of failing scoring. * Contract alignment: The six-factor score weights are unchanged. *** ### Task T012 - Derive and publish per-topic signalAging **Started**: 2026-06-14 04:17 **Completed**: 2026-06-14 04:18 **Duration**: 1 minute **Notes**: * Derived `signalAging` from scoring evidence after saturation and before lifecycle derivation. * Published bounded status, score, age summary, stale/fresh counts, penalties, boosts, confirmation, old-source pressure, and role contributions. * Mapped helper warnings to bounded warning codes for browser payloads. **Files Changed**: * `scripts/lib/ai-runtime/scoring.ts` - Added signal-aging derivation and topic payload wiring. **BQC Fixes**: * Error information boundaries: Browser payload gets warning codes only, not helper diagnostic messages or raw evidence details. * Contract alignment: Contributions are role-based and bounded. *** ### Task T013 - Bump scoring version **Started**: 2026-06-14 04:18 **Completed**: 2026-06-14 04:18 **Duration**: 1 minute **Notes**: * Bumped scoring version from `trend-finder-scoring-v28.4` to `trend-finder-scoring-v28.5` for the half-life recency and refined saturation math change. * Existing scoring-version comparison logic remains unchanged and continues to flag cross-version movement. **Files Changed**: * `scripts/lib/ai-runtime/scoring.ts` - Updated `SCORING_VERSION`. **BQC Fixes**: * Contract alignment: Movement comparisons retain cross-version provenance instead of silently mixing scoring formulas. *** ### Task T014 - Render aging and saturation chips on Trend cards **Started**: 2026-06-14 04:18 **Completed**: 2026-06-14 04:19 **Duration**: 1 minute **Notes**: * Added compact Signal aging and Saturation chips to Trend cards. * Added signal aging to the derived-metric grid. * Chips include accessible labels, keyboard focus rings, and bounded text. **Files Changed**: * `src/extensions/trend-finder/components/trend-card.tsx` - Added aging and saturation chip rendering and signal-aging metric display. **BQC Fixes**: * Accessibility and platform compliance: Informational chips are focusable and expose aria labels plus focus-visible styling. *** ### Task T015 - Add Signal Workbench aging model fields **Started**: 2026-06-14 04:19 **Completed**: 2026-06-14 04:21 **Duration**: 2 minutes **Notes**: * Added signal-aging row fields, labels, sort value, search text, filters, and facets to the Signal Workbench model. * Added `signalAging` as a deterministic sort key. **Files Changed**: * `src/extensions/trend-finder/signal-workbench-model.ts` - Added aging row projection, filter, facet, search, and sort support. **BQC Fixes**: * Contract alignment: Workbench consumes the view-model projection instead of raw helper output. * State freshness on re-entry: Default filters include an explicit `all` aging state so re-created filter objects remain valid. *** ### Task T016 - Add Signal Workbench aging controls **Started**: 2026-06-14 04:21 **Completed**: 2026-06-14 04:21 **Duration**: 1 minute **Notes**: * Added an Aging filter select wired to signal-aging status facets. * The existing native select control preserves keyboard input support and includes the `All` option plus generated status options, including unavailable when present. **Files Changed**: * `src/extensions/trend-finder/components/signal-workbench-controls.tsx` - Added the aging filter control. **BQC Fixes**: * Accessibility and platform compliance: Reused native select behavior with stable label/id wiring. *** ### Task T017 - Update Trend Finder fixtures **Started**: 2026-06-14 04:21 **Completed**: 2026-06-14 04:23 **Duration**: 2 minutes **Notes**: * Added a default `signalAging` object to the fixture topic factory for legacy parse coverage. * Added representative fixture topics for fresh, active, cooling, stale, and unavailable aging states. **Files Changed**: * `src/extensions/trend-finder/fixtures.ts` - Added signal-aging fixture data. **BQC Fixes**: * Contract alignment: Fixture coverage includes the unavailable default and bounded role contributions. *** ### Task T018 - Document half-life aging and refined saturation **Started**: 2026-06-14 04:23 **Completed**: 2026-06-14 04:24 **Duration**: 1 minute **Notes**: * Updated momentum recency documentation to describe source-role half-lives and the invalid-date fallback. * Added shipped `signalAging` payload behavior, unavailable states, and lifecycle non-goals. * Updated saturation documentation with refined inputs and display-derived boundaries. **Files Changed**: * `docs/extensions/trend-finder-scoring.md` - Documented half-life aging and refined saturation. **BQC Fixes**: * Contract alignment: Documentation describes shipped behavior and explicitly excludes lifecycle labels and score multipliers. *** ### Task T019 - Record implementation decisions and validation state **Started**: 2026-06-14 04:24 **Completed**: 2026-06-14 04:24 **Duration**: 1 minute **Notes**: * Added validation command tracking and residual risk notes for the remaining focused test pass. * Design decisions for role-level half-lives and scoring-version bump are already recorded above. **Files Changed**: * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` - Added validation and residual risk sections. *** ## Validation Commands | Command | Status | Notes | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------ | ------------------------------------------------------------------------- | | `bunx vitest run scripts/lib/ai-runtime/__tests__/signal-aging.test.ts` | Passed | 1 file, 5 tests. | | `bunx vitest run scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts` | Passed | 1 file, 15 tests. | | `bunx vitest run scripts/lib/ai-runtime/__tests__/scoring.test.ts` | Passed | 1 file, 35 tests. | | `bunx vitest run src/extensions/trend-finder/__tests__/view-model.test.ts` | Passed | 1 file, 35 tests. | | `bunx vitest run src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` | Passed | 2 files, 13 tests. | | `bunx vitest run scripts/lib/ai-runtime/__tests__/signal-aging.test.ts scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts scripts/lib/ai-runtime/__tests__/scoring.test.ts src/extensions/trend-finder/__tests__/view-model.test.ts src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` | Passed | 6 files, 103 tests. | | `bun run typecheck` | Passed | App TypeScript check completed. | | `bun run typecheck:scripts` | Passed | Script TypeScript check completed. | | ASCII validation for 22 session-touched files | Passed | Checked ASCII bytes and CRLF via `.spec_system/scripts/common.sh` helper. | | `git diff --check` | Passed | No whitespace errors. | *** ## Residual Risks * No unresolved implementation risks remain for this session. * Manual browser UI was not run because the changed card and Workbench surfaces are covered by focused happy-dom component/model tests, and typechecks passed. * Fixture examples remain hand-authored representative states; generated `signalAging` behavior is covered by scoring integration tests. *** ### Task T021 - Add scoring integration tests **Started**: 2026-06-14 04:25 **Completed**: 2026-06-14 04:26 **Duration**: 1 minute **Notes**: * Added scoring coverage for role-specific recency differences, generated `signalAging`, refined saturation, scoring-version bump, and no hidden multiplier in the six-factor raw opportunity score. **Files Changed**: * `scripts/lib/ai-runtime/__tests__/scoring.test.ts` - Added half-life, saturation, and version integration tests. **Validation**: * `bunx vitest run scripts/lib/ai-runtime/__tests__/scoring.test.ts` passed: 1 file, 35 tests. *** ### Task T022 - Add schema and view-model tests **Started**: 2026-06-14 04:26 **Completed**: 2026-06-14 04:28 **Duration**: 2 minutes **Notes**: * Added legacy `signalAging` parse-default coverage. * Added signal-aging label, unavailable reason, contribution, and projection assertions. **Files Changed**: * `src/extensions/trend-finder/__tests__/view-model.test.ts` - Added schema and view-model aging tests. **Validation**: * `bunx vitest run src/extensions/trend-finder/__tests__/view-model.test.ts` passed: 1 file, 35 tests. *** ### Task T020 - Add source-config half-life tests **Started**: 2026-06-14 04:24 **Completed**: 2026-06-14 04:25 **Duration**: 1 minute **Notes**: * Added source-config coverage for half-life role defaults, valid overrides, resolver defaults, invalid bounds, invalid strings, and warning messages. **Files Changed**: * `scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts` - Added half-life metadata tests. **Validation**: * `bunx vitest run scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts` passed: 1 file, 15 tests. *** ### Task T023 - Add Workbench model and Trend card tests **Started**: 2026-06-14 04:29 **Completed**: 2026-06-14 04:33 **Duration**: 4 minutes **Notes**: * Added Workbench coverage for signal-aging projection, fresh-status filtering, aging search text, deterministic signal-aging sort order, and aging status facets including unavailable. * Added Trend card component coverage for focusable aging/saturation chips, aria labels, chip titles, and the signal-aging derived metric. **Files Changed**: * `src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts` - Added signal-aging Workbench assertions. * `src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` - Added Trend card aging chip and derived metric coverage. **Validation**: * `bunx vitest run src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` passed: 2 files, 13 tests. *** ### Task T024 - Run focused tests and ASCII validation **Started**: 2026-06-14 04:33 **Completed**: 2026-06-14 04:35 **Duration**: 2 minutes **Notes**: * Ran the full focused test set for signal aging, source config, scoring, view-model projection, Workbench behavior, and Trend card rendering. * Ran app and script TypeScript checks to validate cross-file type alignment. * Validated ASCII encoding and Unix LF line endings for 22 session-touched files, including spec artifacts, source files, docs, and tests. * Ran `git diff --check`; no whitespace errors were reported. * No separate manual browser UI check was necessary after the focused component/model coverage and typechecks. **Files Changed**: * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/implementation-notes.md` - Recorded final validation results and residual-risk notes. * `.spec_system/specs/phase28-session05-signal-aging-half-lives-and-saturation-refinement/tasks.md` - Marked final testing task and completion checklist. **Validation**: * `bunx vitest run scripts/lib/ai-runtime/__tests__/signal-aging.test.ts scripts/extensions/trend-finder/sources/__tests__/apify-source-config.test.ts scripts/lib/ai-runtime/__tests__/scoring.test.ts src/extensions/trend-finder/__tests__/view-model.test.ts src/extensions/trend-finder/__tests__/signal-workbench-model.test.ts src/extensions/trend-finder/components/__tests__/trend-card.test.tsx` passed: 6 files, 103 tests. * `bun run typecheck` passed. * `bun run typecheck:scripts` passed. * ASCII validation passed for 22 session-touched files. * `git diff --check` passed. *** ### Decision 2: Scoring version bump for display-derived math changes **Context**: This session changes momentum recency and saturation derivation. Even though saturation remains display-derived and the six-factor weights stay unchanged, score ordering can move through the momentum component. **Options Considered**: 1. Keep `trend-finder-scoring-v28.4` - would avoid fixture churn but make cross-version movement look organic. 2. Bump to `trend-finder-scoring-v28.5` - makes comparisons explicit and uses existing mismatch flags. **Chosen**: Bump to `trend-finder-scoring-v28.5`. **Rationale**: Recency math changed and the product already has version comparison fields for this purpose. *** --- # 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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