feat: implement backend computation with progress tracking improvements

Add server-side weight trend calculations, improve progress tracking system,
fix UI issues, and restructure project documentation.

feat(api): add MeasurementComputationService for server-side trend calculations
  - Implement exponentially smoothed moving average (alpha=0.1)
  - Add ComputedMeasurement and SourceMeasurement models
  - Update MeasurementsResponse to use computedMeasurements array
  - Support optional includeSource parameter for raw data access
  - Add comprehensive test coverage for computation service

refactor(web): improve progress tracking system and remove client-side computation
  - Remove client-side computation logic from dashboard hooks
  - Update queries to consume backend-computed measurements
  - Centralize toast management in SyncProgressProvider to prevent duplicates
  - Simplify useSyncProgress API by hiding internal functions
  - Remove redundant useSyncProgressId hook
  - Fix React hooks rule violations with proper useWithProgress wrapper
  - Update all test mocks for new API structure

fix(web): download page skeleton width now matches actual table dimensions

docs: restructure documentation with steering documents and commit guidelines
  - Add steering docs for product, structure, tech, and conventions
  - Document spec-driven development approach
  - Add comprehensive commit message guidelines with multi-topic format
  - Remove outdated architecture and testing docs

Author: ervwalter

AGENT.md

@@ -1,168 +1,7 @@
-# CLAUDE.md
-
-AI-specific guidance for working with the TrendWeight codebase.
-
-## Project Context
-- TrendWeight tracks weight trends using smart scales (Withings/Fitbit)
-- C# ASP.NET Core API backend + Vite React TypeScript frontend
-- Clerk for auth (NOT Supabase Auth), Supabase for PostgreSQL only
-- Project name: **TrendWeight** (capital T, capital W, no space)
-
-## Code Search Strategy
-### Use Semantic Search (mcp__code-context__search_code) for:
-- Conceptual searches (finding code by what it does)
-- Algorithm/calculation implementations
-- Feature exploration across files
-- Cross-cutting concerns (auth, error handling, validation)
-- Initial investigation when location unknown
-
-### Use Direct Tools (Read, Grep, Glob) for:
-- Known file locations
-- Literal string matches, variable names
-- File patterns by extension/naming
-- Configuration values, constants
-- Quick verification of specific lines
-
-### Search Performance:
-- Semantic excels: business logic, UI components, features, tests
-- Semantic struggles: infrastructure config, connection strings, cache settings
-- Direct excels: exact matches, known patterns, config files, imports
-
-## TypeScript/React Rules
-- Use kebab-case for all frontend files (`user-profile.tsx`)
-- Component names in files contents remain PascalCase (`UserProfile`)
-- Enable strict mode, avoid `any` type
-- Use functional components with hooks
-- Cache Intl formatters at module level
-- Use TanStack Query for all API calls
-- Use `ExternalLink` component for external URLs
-- Use standard UI components (Button, Heading, Select, etc) never raw HTML
-
-## Tailwind CSS Rules
-- Use semantic color variables from index.css (e.g., `bg-background`, `text-foreground`)
-- Never use explicit colors (e.g., `bg-gray-500`, `text-blue-600`)
-- Avoid `dark:` prefixes - CSS variables handle theme switching automatically
-- Rare exceptions: only when CSS variables don't cover the specific need
-- Check index.css for available semantic variables before adding styles
-- Semantic colors automatically adapt to light/dark mode
-
-## Route File Pattern (MANDATORY)
-```typescript
-import { createFileRoute } from "@tanstack/react-router";
-import { Layout } from "../components/Layout";
-import { ComponentName } from "../components/feature-folder/ComponentName";
-
-export const Route = createFileRoute("/route-path")({
-  beforeLoad: requireAuth, // Only if needed
-  loader: async () => { }, // Only if needed
-  component: RouteNamePage,
-});
-
-function RouteNamePage() {
-  const { param } = Route.useParams(); // Only if route has params
-  return (
-    <Layout title="Page Title">
-      <ComponentName param={param} />
-    </Layout>
-  );
-}
-```
-- Routes must be minimal (<30 lines)
-- NO business logic, hooks, or UI in routes
-- ALL logic in feature components under `apps/web/src/components/`
-- Feature folders match route purpose
-
-## C# Backend Rules
-- Use feature folders for organization
-- Inherit from `BaseAuthController` for auth endpoints
-- Keep controllers thin, logic in services
-- Use async/await for all I/O
-- Use IOptions<T> for configuration
-- Use JSONB for flexible data storage
-- Use constants for magic numbers
-- Store timestamps as ISO 8601 strings
-- Store weights in kg
-
-## Development Workflow
-### Pre-commit checks (MANDATORY):
-```bash
-npm run check && npm run test
-```
-- Run from root directory only
-- Never skip TypeScript compilation check
-
-### Commit message guidelines:
-- Never use "BREAKING CHANGE" in commit messages
-- This is an application, not a library - there are no breaking changes
-- Use conventional commit format without breaking change notation
-
-### Command locations:
-- Always run commands from repo root
-- Turborepo handles optimization
-- Never run commands in workspace subdirectories
-
-## Testing Requirements
-### Frontend:
-- Use MSW for HTTP mocking (never mock fetch directly)
-- Suppress console for expected errors: `vi.spyOn(console, "error").mockImplementation(() => {})`
-- Test business logic, not framework integration
-
-### Backend:
-- Use xUnit for all tests
-- Extract business logic to testable services
-- Don't test framework integration directly
-
-## Database Guidelines
-- Modify schema in Supabase dashboard
-- Update C# models with `Db` prefix
-- Update schema documentation when changed
-- All timestamps as ISO 8601 strings
-- All weights in kilograms
-
-## Spec-Workflow Rules (MANDATORY)
-- **CRITICAL: ALWAYS call `spec-workflow-guide` BEFORE ANY spec work** - this is the first tool to call when:
-  - User mentions working on a spec or task
-  - User asks to execute/implement a task number
-  - Returning to spec work after any break
-  - After conversation compaction
-- **ALWAYS load full spec context** (requirements, design, tasks) via `get-spec-context` before implementing
-- **NEVER read/write spec files directly** - use spec-workflow tools exclusively:
-  - `spec-workflow-guide` - Load workflow guide first (MANDATORY FIRST STEP)
-  - `get-spec-context` - Load spec documents before work
-  - `manage-tasks` - Update task status and get context
-  - `create-spec-doc` - Create/update spec documents
-- **NEVER assume spec details** from memory after conversation compaction
-
-## Common Pitfalls to Avoid
-- Never add CORS to API (Vite proxy handles it)
-- Never expose exception details to users
-- Avoid unnecessary type assertions
-- Never create files unless absolutely necessary
-- Never proactively create documentation files
-- Always use `git mv` for renaming tracked files
-- Always extract magic numbers to constants
-- Always use standard UI components over raw HTML
-
-## Lessons Learned
-- Functions should sort input data before processing
-- Route files were refactored to minimal pattern - maintain this
-
-## File Update Policy
-**Auto-update this file when learning:**
-- AI-specific coding patterns
-- User coding preferences affecting generation
-- Technical discoveries impacting code generation
-- Lessons that help future AI instances
-
-**Do NOT add:**
-- General architecture info (→ docs/ARCHITECTURE.md)
-- Feature documentation (→ docs/ARCHITECTURE.md)
-- Setup instructions (→ docs/README.md)
-
-## CLAUDE.md Format Guidelines
-- Keep directives as concise bullet points
-- Avoid verbose explanations or human-readable prose
-- Group related items under clear headings
-- Use code examples only when pattern is complex
-- Prefer directive lists over paragraph explanations
-- Remove redundancy - state each rule once
+- Always read the steering docs before doing any planning or coding:
+  - @docs/steering/product.md
+  - @docs/steering/structure.md
+  - @docs/steering/tech.md
+  - @docs/steering/conventions.md
+- Always re-read all steering docs after compacting a conversation.
+- Always keep steering documents up to date as details change over time

apps/api/TrendWeight.Tests/Features/Measurements/Controllers/MeasurementsControllerTests.cs

@@ -23,6 +23,7 @@ public class MeasurementsControllerTests : TestBase
     private readonly Mock<IProfileService> _profileServiceMock;
     private readonly Mock<IProviderIntegrationService> _providerIntegrationServiceMock;
     private readonly Mock<IMeasurementSyncService> _measurementSyncServiceMock;
+    private readonly Mock<IMeasurementComputationService> _measurementComputationServiceMock;
     private readonly Mock<ILogger<MeasurementsController>> _loggerMock;
     private readonly Mock<ICurrentRequestContext> _requestContextMock;
     private readonly MeasurementsController _sut;
@@ -32,6 +33,7 @@ public MeasurementsControllerTests()
         _profileServiceMock = new Mock<IProfileService>();
         _providerIntegrationServiceMock = new Mock<IProviderIntegrationService>();
         _measurementSyncServiceMock = new Mock<IMeasurementSyncService>();
+        _measurementComputationServiceMock = new Mock<IMeasurementComputationService>();
         _loggerMock = new Mock<ILogger<MeasurementsController>>();
         _requestContextMock = new Mock<ICurrentRequestContext>();
         _requestContextMock.SetupAllProperties();
@@ -40,6 +42,7 @@ public MeasurementsControllerTests()
             _profileServiceMock.Object,
             _providerIntegrationServiceMock.Object,
             _measurementSyncServiceMock.Object,
+            _measurementComputationServiceMock.Object,
             _loggerMock.Object,
             _requestContextMock.Object);
     }
@@ -69,6 +72,8 @@ public async Task GetMeasurements_WithValidUser_ReturnsDataWithProviderStatus()
                     { "fitbit", new ProviderSyncStatus { Success = true } }
                 }
             });
+        _measurementComputationServiceMock.Setup(x => x.ComputeMeasurements(sourceData, user.Profile))
+            .Returns(new List<ComputedMeasurement>());
 
         // Act
         var result = await _sut.GetMeasurements();
@@ -78,7 +83,8 @@ public async Task GetMeasurements_WithValidUser_ReturnsDataWithProviderStatus()
         var okResult = result.Result.Should().BeOfType<OkObjectResult>().Subject;
         var response = okResult.Value.Should().BeOfType<MeasurementsResponse>().Subject;
         response.IsMe.Should().Be(true);
-        response.Data.Should().BeEquivalentTo(sourceData);
+        response.ComputedMeasurements.Should().NotBeNull();
+        response.SourceData.Should().BeNull(); // Default includeSource=false
         response.ProviderStatus.Should().NotBeNull();
 
         response.ProviderStatus.Should().HaveCount(2);
@@ -141,6 +147,8 @@ public async Task GetMeasurements_WhenDataNeedsRefresh_RefreshesAndReturnsData()
                     { "withings", new ProviderSyncStatus { Success = true } }
                 }
             });
+        _measurementComputationServiceMock.Setup(x => x.ComputeMeasurements(sourceData, user.Profile))
+            .Returns(new List<ComputedMeasurement>());
 
         // Act
         var result = await _sut.GetMeasurements();
@@ -149,7 +157,8 @@ public async Task GetMeasurements_WhenDataNeedsRefresh_RefreshesAndReturnsData()
         result.Should().NotBeNull();
         var okResult = result.Result.Should().BeOfType<OkObjectResult>().Subject;
         var response = okResult.Value.Should().BeOfType<MeasurementsResponse>().Subject;
-        response.Data.Should().BeEquivalentTo(sourceData);
+        response.ComputedMeasurements.Should().NotBeNull();
+        response.SourceData.Should().BeNull(); // Default includeSource=false
     }
 
     [Fact]
@@ -241,6 +250,8 @@ public async Task GetMeasurementsBySharingCode_WithValidCode_ReturnsDataWithoutP
                     { "withings", new ProviderSyncStatus { Success = true } }
                 }
             });
+        _measurementComputationServiceMock.Setup(x => x.ComputeMeasurements(sourceData, user.Profile))
+            .Returns(new List<ComputedMeasurement>());
 
         // Act
         var result = await _sut.GetMeasurementsBySharingCode(sharingCode);
@@ -250,7 +261,8 @@ public async Task GetMeasurementsBySharingCode_WithValidCode_ReturnsDataWithoutP
         var okResult = result.Result.Should().BeOfType<OkObjectResult>().Subject;
         var response = okResult.Value.Should().BeOfType<MeasurementsResponse>().Subject;
         response.IsMe.Should().Be(false);
-        response.Data.Should().BeEquivalentTo(sourceData);
+        response.ComputedMeasurements.Should().NotBeNull();
+        response.SourceData.Should().BeNull(); // Default includeSource=false
         response.ProviderStatus.Should().BeNull(); // No provider status for shared view
     }
 

apps/api/TrendWeight.Tests/Features/Measurements/Services/MeasurementSyncServiceTests.cs

@@ -7,6 +7,7 @@
 using TrendWeight.Features.Measurements.Models;
 using TrendWeight.Features.Providers;
 using TrendWeight.Features.Providers.Models;
+using TrendWeight.Features.SyncProgress;
 using TrendWeight.Tests.Fixtures;
 using Xunit;
 
@@ -35,7 +36,7 @@ public MeasurementSyncServiceTests()
             _sourceDataServiceMock.Object,
             _loggerMock.Object,
             _environmentMock.Object,
-            null); // ISyncProgressReporter
+            Mock.Of<ISyncProgressReporter>()); // ISyncProgressReporter
     }
 
     #region Constructor Tests
@@ -53,7 +54,7 @@ public void Constructor_InProductionEnvironment_SetsCacheDurationTo300Seconds()
             _sourceDataServiceMock.Object,
             _loggerMock.Object,
             _environmentMock.Object,
-            null); // ISyncProgressReporter
+            Mock.Of<ISyncProgressReporter>()); // ISyncProgressReporter
 
         service.Should().NotBeNull();
     }
@@ -70,7 +71,7 @@ public void Constructor_InDevelopmentEnvironment_SetsCacheDurationTo10Seconds()
             _sourceDataServiceMock.Object,
             _loggerMock.Object,
             _environmentMock.Object,
-            null); // ISyncProgressReporter
+            Mock.Of<ISyncProgressReporter>()); // ISyncProgressReporter
 
         // Assert - This will be tested indirectly through the GetMeasurementsForUserAsync tests
         service.Should().NotBeNull();
@@ -596,7 +597,7 @@ public async Task GetMeasurementsForUserAsync_WithDevelopmentEnvironment_UsesSho
             _sourceDataServiceMock.Object,
             _loggerMock.Object,
             environmentMock.Object,
-            null); // ISyncProgressReporter
+            Mock.Of<ISyncProgressReporter>()); // ISyncProgressReporter
 
         var userId = Guid.NewGuid();
         var activeProviders = new List<string> { "withings" };

apps/api/TrendWeight/Features/Measurements/IMeasurementComputationService.cs

@@ -0,0 +1,19 @@
+using TrendWeight.Features.Measurements.Models;
+using TrendWeight.Features.Profile.Models;
+
+namespace TrendWeight.Features.Measurements;
+
+/// <summary>
+/// Service for computing measurements from raw source data
+/// Contains all computation logic as private methods
+/// </summary>
+public interface IMeasurementComputationService
+{
+    /// <summary>
+    /// Computes measurements from source data for a user
+    /// </summary>
+    /// <param name="sourceData">Raw source data from providers</param>
+    /// <param name="profile">User profile for timezone/preferences</param>
+    /// <returns>Computed measurements with trends</returns>
+    List<ComputedMeasurement> ComputeMeasurements(List<SourceData> sourceData, ProfileData profile);
+}