feat(bluesky): extract external embeds from quoted posts and handle unavailable states

- Extract external link embeds (title, description, thumb) from quoted posts
- Handle blocked quoted posts (#viewBlocked) with "This post is from a blocked account"
- Handle deleted quoted posts (#viewNotFound) with "This post has been deleted"
- Handle detached quoted posts (#viewDetached) with "This post is unavailable"
- Add Detached boolean field for consistency with Blocked/NotFound pattern
- Add logging for JSON unmarshal failures and timestamp parsing errors
- Improve doc comments for embed extraction functions

Also adds beads issue Coves-327 for Phase 3: image/video extraction

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[e-mail]>

.beads/issues.jsonl

···
 {"id":"Coves-fce","content_hash":"26b3e16b99f827316ee0d741cc959464bd0c813446c95aef8105c7fd1e6b09ff","title":"Implement aggregator feed federation","description":"","status":"open","priority":1,"issue_type":"feature","created_at":"2025-11-17T20:30:21.453326012-08:00","updated_at":"2025-11-17T20:30:21.453326012-08:00","source_repo":"."}
 {"id":"Coves-iw5","content_hash":"d3379c617b7583f6b88a0523b3cdd1e4415176877ab00b48710819f2484c4856","title":"Apply functional options pattern to NewGetCommunityHandler","description":"Location: internal/api/handlers/communityFeed/get.go\n\nApply functional options pattern for optional dependencies (votes, bluesky).\n\nDepends on: Coves-jdf (NewPostService refactor should be done first to establish pattern)\nParent: Coves-8k1","status":"open","priority":3,"issue_type":"task","created_at":"2025-12-22T21:35:27.369297201-08:00","updated_at":"2025-12-22T21:35:58.115771178-08:00","source_repo":"."}
 {"id":"Coves-jdf","content_hash":"cb27689d71f44fd555e29d2988f2ad053efb6c565cd4f803ff68eaade59c7546","title":"Apply functional options pattern to NewPostService","description":"Location: internal/core/posts/service.go\n\nCurrent constructor (7 params, 4 optional):\n```go\nfunc NewPostService(repo Repository, communityService communities.Service, aggregatorService aggregators.Service, blobService blobs.Service, unfurlService unfurl.Service, blueskyService blueskypost.Service, pdsURL string) Service\n```\n\nRefactor to:\n```go\ntype Option func(*postService)\n\nfunc WithAggregatorService(svc aggregators.Service) Option\nfunc WithBlobService(svc blobs.Service) Option\nfunc WithUnfurlService(svc unfurl.Service) Option\nfunc WithBlueskyService(svc blueskypost.Service) Option\n\nfunc NewPostService(repo Repository, communityService communities.Service, pdsURL string, opts ...Option) Service\n```\n\nFiles to update:\n- internal/core/posts/service.go (define Option type and With* functions)\n- cmd/server/main.go (production caller)\n- ~15 test files with call sites\n\nStart with this one as it has the most params and is most impacted.\nParent: Coves-8k1","status":"open","priority":2,"issue_type":"task","created_at":"2025-12-22T21:35:27.264325344-08:00","updated_at":"2025-12-22T21:35:58.003863381-08:00","source_repo":"."}
-{"id":"Coves-p44","content_hash":"6f12091f6e5f1ad9812f8da4ecd720e0f9df1afd1fdb593b3e52c32be0193d94","title":"Bluesky embed conversion Phase 2: resolve post and populate CID","description":"When converting a Bluesky URL to a social.coves.embed.post, we need to:\n\n1. Call blueskyService.ResolvePost() to get the full post data including CID\n2. Populate both URI and CID in the strongRef\n3. Consider caching/re-using resolved post data for rendering\n\nCurrently disabled in Phase 1 (text-only) because:\n- social.coves.embed.post requires a valid CID in com.atproto.repo.strongRef\n- Empty CID causes PDS to reject the record creation\n\nRelated files:\n- internal/core/posts/service.go:tryConvertBlueskyURLToPostEmbed()\n- internal/atproto/lexicon/social/coves/embed/post.json\n\nThis is part of the Bluesky post cross-posting feature (images/embeds phase).","status":"open","priority":2,"issue_type":"feature","created_at":"2025-12-22T21:25:23.540135876-08:00","updated_at":"2025-12-22T21:25:41.704980685-08:00","source_repo":"."}
+{"id":"Coves-p44","content_hash":"6f12091f6e5f1ad9812f8da4ecd720e0f9df1afd1fdb593b3e52c32be0193d94","title":"Bluesky embed conversion Phase 2: resolve post and populate CID","description":"When converting a Bluesky URL to a social.coves.embed.post, we need to:\n\n1. Call blueskyService.ResolvePost() to get the full post data including CID\n2. Populate both URI and CID in the strongRef\n3. Consider caching/re-using resolved post data for rendering\n\nCurrently disabled in Phase 1 (text-only) because:\n- social.coves.embed.post requires a valid CID in com.atproto.repo.strongRef\n- Empty CID causes PDS to reject the record creation\n\nRelated files:\n- internal/core/posts/service.go:tryConvertBlueskyURLToPostEmbed()\n- internal/atproto/lexicon/social/coves/embed/post.json\n\nThis is part of the Bluesky post cross-posting feature (images/embeds phase).","status":"closed","priority":2,"issue_type":"feature","created_at":"2025-12-22T21:25:23.540135876-08:00","updated_at":"2025-12-23T14:41:49.014541876-08:00","closed_at":"2025-12-23T14:41:49.014541876-08:00","source_repo":"."}
 {"id":"Coves-r6n","content_hash":"48a9b995bdef6efcfa2c42d5620cc262b264d3dfe7c265423aaed7ee8890a2f2","title":"Community handle names limited to 16 characters due to PDS hardcoded limit","description":"## Summary\nThe Bluesky PDS has a hardcoded 18-character limit on the first segment of handles (packages/pds/src/handle/index.ts line 89). With our `c-` prefix for community handles, this limits community names to 16 characters.\n\n## Affected Names\nNames like `artificial-intelligence` (23 chars), `software-engineering` (20 chars), or `explain-like-im-five` (20 chars) won't work.\n\n## Background\n- AT Protocol spec allows 63 chars per segment (DNS label limit)\n- PDS limit is a Bluesky policy choice for `*.bsky.social` usability\n- Fix was discussed in https://github.com/bluesky-social/atproto/issues/2391\n- PR https://github.com/bluesky-social/atproto/pull/2392 changed from 30 total to 18 first-segment\n\n## Resolution Options\n1. **Fork PDS** - Change `if (front.length \u003e 18)` to higher limit (e.g., 30 or 63)\n2. **Accept limit** - Document 16-char max for community names\n3. **Remove c- prefix** - Gains 2 chars but loses user/community distinction\n\n## Decision\nAccepting the limit for now. Most community names fit. Revisit if user demand arises.","status":"open","priority":3,"issue_type":"task","created_at":"2025-12-22T22:06:34.355515838-08:00","updated_at":"2025-12-22T22:06:49.297076332-08:00","source_repo":"."}

internal/core/blueskypost/fetcher.go

···
 // blueskyAPIEmbedRecord represents a quoted post embed in the API response
 // For record#view: this directly contains the viewRecord fields
 // For recordWithMedia#view: this contains a nested "record" field with viewRecord
+// For record#viewBlocked: contains blocked=true and limited author info
+// For record#viewNotFound: contains notFound=true
 type blueskyAPIEmbedRecord struct {
+	// Type identifies the record view type ($type field)
+	// Can be: app.bsky.embed.record#viewRecord, #viewBlocked, #viewNotFound, #viewDetached
+	Type string `json:"$type,omitempty"`
+
+	// Blocked is true when there is a block relationship between viewer and quoted post author
+	Blocked bool `json:"blocked,omitempty"`
+
+	// NotFound is true when the quoted post has been deleted
+	NotFound bool `json:"notFound,omitempty"`
+
+	// Detached is true when the quoted post has been detached (removed from quote context)
+	Detached bool `json:"detached,omitempty"`
+
 	// For recordWithMedia#view - nested structure
 	Record *blueskyAPIViewRecord `json:"record,omitempty"`
 
 	// For record#view - direct viewRecord fields
-	URI       string                   `json:"uri,omitempty"`
-	CID       string                   `json:"cid,omitempty"`
-	Author    *blueskyAPIAuthor        `json:"author,omitempty"`
-	Value     *blueskyAPIRecordValue   `json:"value,omitempty"`
-	LikeCount int                      `json:"likeCount,omitempty"`
-	ReplyCount int                     `json:"replyCount,omitempty"`
-	RepostCount int                    `json:"repostCount,omitempty"`
-	IndexedAt string                   `json:"indexedAt,omitempty"`
-	Embeds    []json.RawMessage        `json:"embeds,omitempty"`
+	URI        string                 `json:"uri,omitempty"`
+	CID        string                 `json:"cid,omitempty"`
+	Author     *blueskyAPIAuthor      `json:"author,omitempty"`
+	Value      *blueskyAPIRecordValue `json:"value,omitempty"`
+	LikeCount  int                    `json:"likeCount,omitempty"`
+	ReplyCount int                    `json:"replyCount,omitempty"`
+	RepostCount int                   `json:"repostCount,omitempty"`
+	IndexedAt  string                 `json:"indexedAt,omitempty"`
+	Embeds     []json.RawMessage      `json:"embeds,omitempty"`
 }
 
 // blueskyAPIViewRecord represents the viewRecord structure for quoted posts
···
 }
 
 // mapViewRecordToResult maps a blueskyAPIEmbedRecord (with direct viewRecord fields) to BlueskyPostResult
-// This is used for app.bsky.embed.record#view where the viewRecord fields are at the top level
+// This is used for app.bsky.embed.record#view where the viewRecord fields are at the top level.
+// Handles unavailable states: blocked (#viewBlocked), deleted (#viewNotFound), and detached (#viewDetached).
 func mapViewRecordToResult(embedRecord *blueskyAPIEmbedRecord) *BlueskyPostResult {
 	if embedRecord == nil {
 		return nil
 	}
 
+	// Handle blocked quoted posts (app.bsky.embed.record#viewBlocked)
+	if embedRecord.Blocked || embedRecord.Type == "app.bsky.embed.record#viewBlocked" {
+		result := &BlueskyPostResult{
+			URI:         embedRecord.URI,
+			Unavailable: true,
+			Message:     "This post is from a blocked account",
+		}
+		// Include author DID if available (handle won't be available for blocked users)
+		if embedRecord.Author != nil {
+			result.Author = &Author{
+				DID: embedRecord.Author.DID,
+			}
+		}
+		return result
+	}
+
+	// Handle deleted/not found quoted posts (app.bsky.embed.record#viewNotFound)
+	if embedRecord.NotFound || embedRecord.Type == "app.bsky.embed.record#viewNotFound" {
+		return &BlueskyPostResult{
+			URI:         embedRecord.URI,
+			Unavailable: true,
+			Message:     "This post has been deleted",
+		}
+	}
+
+	// Handle detached quoted posts (app.bsky.embed.record#viewDetached)
+	if embedRecord.Detached || embedRecord.Type == "app.bsky.embed.record#viewDetached" {
+		return &BlueskyPostResult{
+			URI:         embedRecord.URI,
+			Unavailable: true,
+			Message:     "This post is unavailable",
+		}
+	}
+
 	result := &BlueskyPostResult{
 		URI:         embedRecord.URI,
 		CID:         embedRecord.CID,
···
 			createdAt, err := time.Parse(time.RFC3339, embedRecord.Value.CreatedAt)
 			if err == nil {
 				result.CreatedAt = createdAt
+			} else {
+				log.Printf("[BLUESKY] Warning: Failed to parse CreatedAt timestamp %q for quoted post %s: %v",
+					embedRecord.Value.CreatedAt, embedRecord.URI, err)
 			}
 		}
 	}
 
-	// Check for media in embeds array
+	// Check for media in embeds array and extract external embed if present
 	if len(embedRecord.Embeds) > 0 {
 		result.HasMedia = true
 		result.MediaCount = len(embedRecord.Embeds)
+
+		// Try to extract external embed from the embeds array
+		result.Embed = extractExternalEmbedFromEmbeds(embedRecord.Embeds)
 	}
 
 	return result
 }
 
+// extractExternalEmbedFromEmbeds parses the embeds array and extracts external link embed if present.
+// This is used for quoted posts where embeds are in a nested json.RawMessage array,
+// unlike top-level posts where External is directly available on blueskyAPIEmbed.
+// Returns nil if no external embed is found.
+func extractExternalEmbedFromEmbeds(embeds []json.RawMessage) *ExternalEmbed {
+	for _, embedRaw := range embeds {
+		// Parse the embed to check its type
+		var embedWrapper struct {
+			Type     string `json:"$type"`
+			External *struct {
+				URI         string `json:"uri"`
+				Title       string `json:"title"`
+				Description string `json:"description"`
+				Thumb       string `json:"thumb"`
+			} `json:"external"`
+		}
+
+		if err := json.Unmarshal(embedRaw, &embedWrapper); err != nil {
+			log.Printf("[BLUESKY] Warning: Failed to unmarshal embed in quoted post: %v", err)
+			continue
+		}
+
+		// Check for external embed type
+		if embedWrapper.Type == "app.bsky.embed.external#view" && embedWrapper.External != nil {
+			return &ExternalEmbed{
+				URI:         embedWrapper.External.URI,
+				Title:       embedWrapper.External.Title,
+				Description: embedWrapper.External.Description,
+				Thumb:       embedWrapper.External.Thumb,
+			}
+		}
+	}
+
+	return nil
+}
+
 // mapNestedViewRecordToResult maps a blueskyAPIViewRecord to BlueskyPostResult
 // This is used for app.bsky.embed.recordWithMedia#view where the viewRecord is nested
 func mapNestedViewRecordToResult(viewRecord *blueskyAPIViewRecord) *BlueskyPostResult {
···
 			createdAt, err := time.Parse(time.RFC3339, viewRecord.Value.CreatedAt)
 			if err == nil {
 				result.CreatedAt = createdAt
+			} else {
+				log.Printf("[BLUESKY] Warning: Failed to parse CreatedAt timestamp %q for quoted post %s: %v",
+					viewRecord.Value.CreatedAt, viewRecord.URI, err)
 			}
 		}
 	}
 
-	// Check for media in embeds array
+	// Check for media in embeds array and extract external embed if present
 	if len(viewRecord.Embeds) > 0 {
 		result.HasMedia = true
 		result.MediaCount = len(viewRecord.Embeds)
+
+		// Try to extract external embed from the embeds array
+		result.Embed = extractExternalEmbedFromEmbeds(viewRecord.Embeds)
 	}
 
 	return result