Add exact title match search, newsletter dark theme, and background job safe defaults (#456)

* Add exact title match search and newsletter fixes

Summary: Adds exact title match search used by newsletter links, restyle
newsletter emails to the site's dark theme, and make all background job
enabled flags default to false with only production explicitly enabling them.

Implementation:
• Add ExactTitleMatch to SearchRequest with cache key support
• Add exact ILIKE query path in ContentRepository
• Expose exact=true query param on content search API endpoint
• Propagate exact param through ITechHubApiClient and TechHubApiClient
• Add ExactMatch mode to ContentItemsGrid and SectionCollection page
• Restyle newsletter email templates (daily + weekly) to dark purple theme
• Default ContentProcessorOptions.Enabled, RoundupGeneratorOptions.Enabled,
  and NewsletterOptions.ScheduledSendEnabled to false (C# bool default)
• Enable all three background jobs explicitly in appsettings.Production.json
• Update bicep backgroundJobEnvVars comment for new config layout
• Delete obsolete appsettings.Staging.json from both Api and Web projects
• Update Web component tests for new ContentItemsGrid/Section signatures

* Clarify daily email behavior on subscribe page

* Address PR review comments: fix exact-match bugs, staging config, and add tests

- Fix ILIKE substring match: use bare query (no %wildcards%) in exact mode
- Fix exact=false treated as exact: use string.Equals(..., 'true') instead of IsNullOrWhiteSpace
- Fix tags not cleared in exact mode: pass Array.Empty<string>() when exactMode
- Add exactMode guard: exact=true without query behaves as normal request
- Replace bicep enableBackgroundJobs env var with appsettings.Staging.json for PR preview environments
- Add 5 integration tests for exact title matching behaviour
- Fix pre-existing test bug: TriggerImmediateRun_WhenEnabled_ExecutesManualRun missing Enabled=true

* Add exact phrase match checkbox to sidebar; fix exact mode to use phrase containment

- SidebarSearch: add 'Exact title match' checkbox below search input (visible only when query is non-empty)
- SidebarSearch: new ExactMatch parameter and OnExactMatchChanged callback
- SidebarSearch.css: checkbox label styled with design tokens
- SectionCollection: wire checkbox to isExactMatch state and HandleExactMatchChanged
- ContentRepository: fix exact mode ILIKE to use %query% (phrase containment) instead of bare equality
  - 'vscode update' now matches titles containing 'vscode update', not just titles equal to it
  - newsletter links (exact=true + full title) continue to work correctly
- ContentEndpointsTests: update tests to match phrase-containment semantics; rename DoesNotMatchSubstrings to MatchesByPhrase
- SidebarSearchTests: add 4 bUnit tests for checkbox visibility, checked state, and change event
- docs/filtering.md: document exact phrase match mode, URL parameter, and checkbox interaction

* Fix ContentItemsGrid double-load when exact=true on first render

Initialize previousExactMatch from ExactMatch in OnInitializedAsync alongside all other previous* fields. Without this, navigating to a URL with ?exact=true caused OnParametersSetAsync to immediately detect a mismatch (false vs true) and fire a redundant LoadInitialBatch.

Author: rvanmaanen

docs/filtering.md

@@ -34,6 +34,7 @@ This enables auto-complete-style search behavior where users don't need to type
 - Clear button (X icon) to remove the search query
 - Keyboard support (Escape key clears the search)
 - URL parameter synchronization (`?search=query`)
+- **Exact phrase match checkbox** — visible when a query is entered; activates exact phrase mode (see below)
 
 **Backend**: Full-text search is implemented at the database level:
 
@@ -62,6 +63,7 @@ Search state is preserved in the URL for sharing and bookmarking:
 ?search=copilot                          # Search only
 ?search=copilot&tags=ai                  # Search + tag filter
 ?search=copilot&tags=ai&from=2024-01-01  # Search + tag + date filter
+?search=vscode+update&exact=true         # Exact phrase match
 ```
 
 **Implementation Details**:
@@ -71,6 +73,32 @@ Search state is preserved in the URL for sharing and bookmarking:
 - Combined with `tags`, `from`, `to` parameters
 - Supports browser back/forward navigation
 
+### Exact Phrase Match
+
+When `?exact=true` is present together with a non-empty `?search=` value, the full-text search engine is bypassed and replaced with a case-insensitive **phrase containment** check on the title:
+
+```sql
+WHERE title ILIKE '%<query>%'
+```
+
+- **"vscode update"** matches "VSCode Update 1.90", "The VSCode Update you missed", etc.
+- **"vscode update"** does **not** match "VSCode tips" — "update" is missing from that title.
+- Date, tag, and content-type filters are **ignored** in exact phrase mode.
+- Results are sorted by date (newest first), not by relevance rank.
+
+**Use cases**:
+
+- **Newsletter links** — each daily-update item links back to the website with `?search={title}&exact=true` so the linked page always shows only that item regardless of the current date range.
+- **Sidebar checkbox** — the "Exact title match" checkbox under the search box activates this mode interactively. It appears only when the search field has text. Typing a new query automatically deactivates exact mode.
+
+If `?exact=true` is present but `?search=` is empty or absent, it is ignored and normal filtering applies (including the default date range).
+
+**API parameter**: `exact` (boolean, passed as `true`/`false` string). Example:
+
+```bash
+curl -k "https://localhost:5001/api/sections/ai/collections/all/items?q=vscode+update&exact=true"
+```
+
 ## Tag Storage and Expansion
 
 ### How Tags Are Stored

infra/modules/api.bicep

@@ -50,9 +50,6 @@ param newsletterUnsubscribeSecretName string = ''
 @description('ASPNETCORE_ENVIRONMENT value. Use "Staging" for PR preview environments.')
 param aspNetCoreEnvironment string = 'Production'
 
-@description('When false, disables scheduled background jobs (ContentProcessor, RoundupGenerator). Set to false for PR preview environments.')
-param enableBackgroundJobs bool = true
-
 @description('Minimum replica count. Use 0 to enable scale-to-zero for PR preview environments.')
 param minReplicas int = 1
 
@@ -73,16 +70,6 @@ var corsEnvVars = [for (fqdn, i) in webFqdns: {
   name: 'Cors__AllowedOrigins__${i}'
   value: 'https://${fqdn}'
 }]
-var backgroundJobEnvVars = enableBackgroundJobs ? [] : [
-  {
-    name: 'ContentProcessor__Enabled'
-    value: 'false'
-  }
-  {
-    name: 'RoundupGenerator__Enabled'
-    value: 'false'
-  }
-]
 var newsletterSecretEnvVars = empty(newsletterUnsubscribeSecretName)
   ? []
   : [
@@ -253,7 +240,7 @@ resource api 'Microsoft.App/containerApps@2025-07-01' = {
             cpu: json('0.25')
             memory: '0.5Gi'
           }
-          env: concat(staticEnvVars, newsletterAcsEnvVars, newsletterSenderEnvVars, newsletterSecretEnvVars, corsEnvVars, backgroundJobEnvVars)
+          env: concat(staticEnvVars, newsletterAcsEnvVars, newsletterSenderEnvVars, newsletterSecretEnvVars, corsEnvVars)
           probes: [
             {
               type: 'startup'

infra/pr-applications.bicep

@@ -90,7 +90,6 @@ module apiApp './modules/api.bicep' = {
     aiCategorizationEndpoint: '' // AI categorization disabled (background jobs are off)
     aiCategorizationDeploymentName: ''
     aspNetCoreEnvironment: 'Staging'
-    enableBackgroundJobs: false // prevent PR from triggering content sync / roundup jobs
     minReplicas: 0 // scale to zero when idle to minimize cost
     maxReplicas: 1
   }

src/TechHub.Api/Endpoints/ContentEndpoints.cs

@@ -264,6 +264,7 @@ private static async Task<Results<Ok<CollectionItemsResponse>, NotFound, BadRequ
         [FromQuery] string? from = null,
         [FromQuery] string? to = null,
         [FromQuery] string? types = null,
+        [FromQuery] bool exact = false,
         CancellationToken cancellationToken = default)
     {
         sectionName = sectionName.Sanitize();
@@ -360,9 +361,12 @@ private static async Task<Results<Ok<CollectionItemsResponse>, NotFound, BadRequ
             (dateFrom, dateTo) = (dateTo, dateFrom);
         }
 
-        // Build collections array - when "all" and types specified, filter to specific collection types
+        // Build collections array - when "all" and types specified, filter to specific collection types.
+        // When exact=true, types are ignored (exact match covers all collections).
+        // Exact mode requires a non-empty query; without one, behave as a normal request.
+        var exactMode = exact && !string.IsNullOrWhiteSpace(q);
         string[] collectionsArray;
-        if (isAllCollection && !string.IsNullOrWhiteSpace(types))
+        if (!exactMode && isAllCollection && !string.IsNullOrWhiteSpace(types))
         {
             // Validate types against section's actual non-custom collections
             var validCollectionNames = section.Collections
@@ -384,16 +388,18 @@ private static async Task<Results<Ok<CollectionItemsResponse>, NotFound, BadRequ
             collectionsArray = new[] { collectionName };
         }
 
-        // Build search request - repository will handle "all" as no filter
+        // Build search request - repository will handle "all" as no filter.
+        // When exact=true, skip date and tag filters (exact match is purely title-based).
         var request = new SearchRequest(
             take: limit,
             skip: offset,
             query: q,
             sections: new[] { section.Name },
             collections: collectionsArray,
-            tags: parsedTags ?? Array.Empty<string>(),
-            dateFrom: dateFrom,
-            dateTo: dateTo
+            tags: exactMode ? Array.Empty<string>() : (parsedTags ?? Array.Empty<string>()),
+            dateFrom: exactMode ? null : dateFrom,
+            dateTo: exactMode ? null : dateTo,
+            exactTitleMatch: exactMode
         );
 
         var content = await contentRepository.SearchAsync(request, cancellationToken);

src/TechHub.Api/appsettings.Development.json

@@ -13,7 +13,6 @@
     ]
   },
   "Newsletter": {
-    "ScheduledSendEnabled": false,
     "ConnectionString": "",
     "SenderAddress": "",
     "WebsiteBaseUrl": "https://localhost:5003"

src/TechHub.Api/appsettings.Production.json

@@ -12,5 +12,14 @@
       "https://tech.hub.ms",
       "https://tech.xebia.ms"
     ]
+  },
+  "ContentProcessor": {
+    "Enabled": true
+  },
+  "RoundupGenerator": {
+    "Enabled": true
+  },
+  "Newsletter": {
+    "ScheduledSendEnabled": true
   }
 }

src/TechHub.Api/appsettings.Staging.json

@@ -1,14 +1,11 @@
 {
-  "AppSettings": {
-    "BaseUrl": "https://staging-tech.hub.ms"
+  "ContentProcessor": {
+    "Enabled": false
   },
-  "Database": {
-    "Provider": "PostgreSQL",
-    "ConnectionString": ""
+  "RoundupGenerator": {
+    "Enabled": false
   },
-  "Cors": {
-    "AllowedOrigins": [
-      "https://staging-tech.hub.ms"
-    ]
+  "Newsletter": {
+    "ScheduledSendEnabled": false
   }
 }

src/TechHub.Api/appsettings.json

@@ -421,7 +421,6 @@
     "MaxRetries": 3
   },
   "Newsletter": {
-    "ScheduledSendEnabled": false,
     "ConnectionString": "",
     "SenderAddress": "",
     "WebsiteBaseUrl": "",

src/TechHub.Core/Configuration/ContentProcessorOptions.cs

@@ -9,12 +9,11 @@ public class ContentProcessorOptions
     public const string SectionName = "ContentProcessor";
 
     /// <summary>
-    /// Whether scheduled content processing is enabled. Defaults to true.
-    /// Set <c>ContentProcessor__Enabled=false</c> via environment variable to disable scheduling
-    /// in environments where automatic processing should not run (e.g. PR preview environments).
+    /// Whether scheduled content processing is enabled. Defaults to false.
+    /// Set to <c>true</c> only in production via <c>appsettings.Production.json</c>.
     /// Manual admin-triggered runs are unaffected by this setting.
     /// </summary>
-    public bool Enabled { get; init; } = true;
+    public bool Enabled { get; init; }
 
     /// <summary>How often to run the content processing pipeline (in minutes).</summary>
     public int IntervalMinutes { get; init; } = 60;

src/TechHub.Core/Configuration/NewsletterOptions.cs

@@ -4,6 +4,10 @@ public sealed class NewsletterOptions
 {
     public const string SectionName = "Newsletter";
 
+    /// <summary>
+    /// Whether scheduled newsletter sending is enabled. Defaults to false.
+    /// Set to <c>true</c> only in production via <c>appsettings.Production.json</c>.
+    /// </summary>
     public bool ScheduledSendEnabled { get; init; }
     public string Endpoint { get; init; } = string.Empty;
     public string SenderAddress { get; init; } = string.Empty;