feat: extract files from message logs

docs/current-status-card.md

@@ -50,7 +50,7 @@ N13/N14/N15 are pre-business validation results. They can help identify UI eleme
 
 ## Current loop
 
-Current loop: `Stage C / Loop C13 - log-backed file metadata extraction`.
+Current loop: `Stage C / Loop C14 - register isphere_receive_files list mode`.
 
 Plan file: `docs/superpowers/plans/2026-07-09-stage-c-log-backed-receive-messages-loop.md`.
 
@@ -75,10 +75,11 @@ Current loop output so far:
 10. C10: log-backed group candidate extraction from groupchat/conference JIDs.
 11. C11: `isphere_search_groups` MCP registration and seven-tool verification.
 12. C12: file evidence precheck confirmed enough PacketReader/Smark evidence for file metadata listing, but not enough for real cache/download mapping.
+13. C13: `internal/isphere.ListFilesFromMessages` extracts synthetic/redacted file metadata candidates from normalized messages; MCP registration is next.
 
 ## Next business mainline
 
-1. Run Stage C Loop C13: implement log-backed file metadata extraction from normalized messages.
-2. Register `isphere_receive_files` list mode after C13 source behavior passes; leave actual download/cache mapping as a later connector node.
+1. Run Stage C Loop C14: register `isphere_receive_files` list mode on top of `ListFilesFromMessages`.
+2. Leave actual download/cache mapping as a later connector node until a message-to-cache hash or client download source is validated.
 3. Add `isphere_send_message` and `isphere_send_file` after source discovery and connector selection.
 4. Keep UIA selector/report work as fallback support, not as the primary roadmap.

docs/source-discovery/capability-source-matrix.md

@@ -20,7 +20,7 @@ Schema notes: `docs/source-discovery/2026-07-09-n12-pre-zyl-schema-notes.md`
 | `isphere_receive_messages` | decrypted `PacketReader.ProcessPacket` XMPP `<message>` stanzas via `internal/isphere.EncryptedPacketLogSource` | decrypted `Smark.SendReceive` transport stanzas; decrypted `SaveToDB` `Chat_OnMessageArrived` traces; wrapped `MsgLib.db` after DB wrapper is solved | `docs/source-discovery/2026-07-09-n12-pre-zyl-schema-notes.md#field-mapping-evidence` | C5 env loader wired through ISPHERE_PACKET_LOG_FILE; default source remains empty when unset | fixture-backed configured-source operator smoke |
 | `isphere_search_contacts` | bare sender/receiver JIDs extracted from normalized log-backed messages | decrypted roster/contact stanzas from `Smark.SendReceive`; `MsgLib.db` contact/conversation tables after DB wrapper is solved; UIA helper source if display names are missing | `docs/source-discovery/2026-07-09-n12-pre-zyl-schema-notes.md#log-decryption-result` | C8 MCP tool registered and verify-go-mcp covers default/configured contact smoke; JID-only display/account fallback | enrich display names from roster/db/uia evidence |
 | `isphere_search_groups` | decrypted `PacketReader.ProcessPacket` `type="groupchat"` stanzas and conference/MUC JIDs | `MsgLib.db` group/conversation tables after DB wrapper is solved; UIA helper source if group display names are missing | C9 ignored-log scan: PacketReader 86 groupchat/86 conference hits; Smark 24 groupchat/658 conference/631 muc hits | C11 MCP tool registered and verify-go-mcp covers default/configured group smoke; JID-only display fallback | enrich group display/member data from roster/db/uia evidence |
-| `isphere_receive_files` | decrypted `PacketReader.ProcessPacket` file-transfer message stanzas for metadata listing; `zyl\importal\<hash>` cache entries remain unlinked | decrypted `Smark.SendReceive` and `SaveToDB` traces for file-reference reconciliation; future UIA/client connector for download | `docs/source-discovery/2026-07-09-n12-pre-zyl-schema-notes.md#c12-file-transfer-evidence-precheck` | C12 evidence confirmed metadata-list source: PacketReader has 107 parsed file candidates; no log-to-cache/download mapping yet | extract file metadata candidates from normalized messages |
+| `isphere_receive_files` | decrypted `PacketReader.ProcessPacket` file-transfer message stanzas for metadata listing via `internal/isphere.ListFilesFromMessages`; `zyl\importal\<hash>` cache entries remain unlinked | decrypted `Smark.SendReceive` and `SaveToDB` traces for file-reference reconciliation; future UIA/client connector for download | `docs/source-discovery/2026-07-09-n12-pre-zyl-schema-notes.md#c12-file-transfer-evidence-precheck` | C13 source behavior implemented for metadata listing; no log-to-cache/download mapping yet | register `isphere_receive_files` MCP list mode |
 
 ## Stage C entry rule
 

docs/superpowers/plans/2026-07-09-stage-c-log-backed-receive-messages-loop.md

@@ -1277,7 +1277,7 @@ Evidence precheck result:
 - Query supports `ConversationID`, `MessageID`, `FileID`, `NameContains`, and `Limit`; default/zero limit returns all candidates.
 - This loop does not register the MCP tool yet. Registration/list-mode smoke becomes C14 after source behavior passes tests.
 
-- [ ] **Step 1: Write failing file extraction test**
+- [x] **Step 1: Write failing file extraction test**
 
 Create `internal/isphere/files_test.go` and run:
 
@@ -1287,11 +1287,11 @@ go test ./internal/isphere -run TestListFilesFromMessagesExtractsFileTransferCan
 
 Expected initial failure: file query/types/functions do not exist.
 
-- [ ] **Step 2: Implement file metadata extraction/search**
+- [x] **Step 2: Implement file metadata extraction/search**
 
 Create `internal/isphere/files.go` with minimal pure Go logic over normalized messages and synthetic/redacted fixtures.
 
-- [ ] **Step 3: Run full verification and rewrite Loop C14**
+- [x] **Step 3: Run full verification and rewrite Loop C14**
 
 Run:
 
@@ -1306,6 +1306,74 @@ Expected: all exit 0. Remove any generated root `isphere-mcp.exe` after build. R
 
 ---
 
+## Loop C13 Result
+
+Implemented and verified in this loop:
+
+- `internal/isphere.ListFilesFromMessages(messages, query)` extracts read-only file metadata candidates from normalized messages when `Subject` contains `FILE_TRANSFER` or message text contains a supported file extension.
+- File metadata currently includes stable local `FileID` (`message_id:file_name`), `MessageID`, `ConversationID`, `FileName`, inferred `MimeType`, `CreatedAt`, `Source` `local_readonly`, and `RawRef` `packetlog_file_transfer`.
+- `SizeBytes`, `DownloadRef`, `SavedPath`, and `SHA256` remain empty/unknown because C12 did not prove a message-to-cache/download mapping.
+- Query matching supports conversation, message, file id, file-name substring, and limit. Tests use only synthetic/redacted filenames.
+- Verification completed for C13 with the loop-specific RED/GREEN test; full verification is run again before commit.
+
+---
+
+## Loop C14: Register `isphere_receive_files` MCP list mode
+
+**Goal:** Register the `isphere_receive_files` MCP tool in list mode on top of C13 file metadata extraction, while making download mode explicitly deferred until cache/download mapping is validated.
+
+**Planned files:**
+- Create: `internal/tools/isphere_files.go`
+- Create: `internal/tools/isphere_files_test.go`
+- Modify: `internal/mcpserver/server.go`
+- Modify: `internal/mcpserver/server_test.go`
+- Modify: `scripts/verify-go-mcp.ps1`
+- Modify: `docs/go-mcp-runbook.md`
+- Modify: `docs/current-status-card.md`
+- Modify: `docs/source-discovery/capability-source-matrix.md`
+- Modify: `docs/superpowers/plans/2026-07-09-stage-c-log-backed-receive-messages-loop.md`
+
+**Planned interface:**
+- Tool name: `isphere_receive_files`.
+- Input: `conversation_id`, `message_id`, `file_id`, `name_contains`, `mode`, `limit`.
+- C14 supports `mode` empty or `list`; download mode is not implemented in this loop.
+- Source: same env-configured receive-message source used by receive/contact/group tools.
+- Output shape: `ok`, `mode`, `files`, `next_cursor`, and `audit`, aligned with `docs/mcp-core-tools-contract.md`.
+- Default empty source returns `ok: true`, `mode: "list"`, `files: []`.
+
+- [ ] **Step 1: Write failing MCP tool test**
+
+Create `internal/tools/isphere_files_test.go` and run:
+
+```powershell
+go test ./internal/tools -run TestISphereReceiveFilesToolReturnsLogBackedFiles -v
+```
+
+Expected initial failure: file receive tool registration does not exist.
+
+- [ ] **Step 2: Implement file tool registration**
+
+Register `isphere_receive_files` with source injection for tests. Use `ListFilesFromMessages` and return a contract-shaped map with minimal audit metadata.
+
+- [ ] **Step 3: Wire server and verification**
+
+Register file receive in server construction. Update server tool-count tests and `scripts/verify-go-mcp.ps1` to expect eight tools and call `isphere_receive_files` against default empty source and synthetic configured file-transfer fixture.
+
+- [ ] **Step 4: Run full verification and commit**
+
+Run:
+
+```powershell
+git diff --check
+go test ./...
+go build ./cmd/isphere-mcp
+powershell -NoProfile -ExecutionPolicy Bypass -File scripts/verify-go-mcp.ps1
+```
+
+Expected: all exit 0. Remove any generated root `isphere-mcp.exe` after build. Commit exact C14 paths only and rewrite the next loop from actual results.
+
+---
+
 ## Self-Review
 
 - Spec coverage: the plan follows the user's cyclic requirement: plan first, implement one loop at a time, update the next loop after each result, and ask only on blockers.

internal/isphere/files.go

@@ -0,0 +1,142 @@
+package isphere
+
+import (
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+type File struct {
+	FileID         string
+	MessageID      string
+	ConversationID string
+	FileName       string
+	SizeBytes      *int64
+	MimeType       string
+	CreatedAt      string
+	DownloadRef    string
+	SavedPath      string
+	SHA256         string
+	Source         string
+	RawRef         string
+}
+
+type ListFilesQuery struct {
+	ConversationID string
+	MessageID      string
+	FileID         string
+	NameContains   string
+	Limit          int
+}
+
+type ListFilesResult struct {
+	Files []File
+}
+
+var fileNamePattern = regexp.MustCompile(`(?i)[^\s<>:"|?*]+\.(?:docx?|xlsx?|pptx?|pdf|zip|rar|png|jpe?g|txt|csv)\b`)
+
+func ListFilesFromMessages(messages []Message, query ListFilesQuery) ListFilesResult {
+	files := make([]File, 0)
+	for _, message := range messages {
+		if !messageLooksFileBacked(message) {
+			continue
+		}
+		fileName := extractMessageFileName(message.Text)
+		if fileName == "" {
+			continue
+		}
+		file := File{
+			FileID:         fileID(message.ID, fileName),
+			MessageID:      message.ID,
+			ConversationID: message.ConversationID,
+			FileName:       fileName,
+			MimeType:       mimeTypeForFileName(fileName),
+			CreatedAt:      message.Timestamp,
+			Source:         "local_readonly",
+			RawRef:         "packetlog_file_transfer",
+		}
+		if fileMatchesQuery(file, query) {
+			files = append(files, file)
+		}
+	}
+
+	sort.Slice(files, func(i, j int) bool {
+		if files[i].FileID == files[j].FileID {
+			return files[i].MessageID < files[j].MessageID
+		}
+		return files[i].FileID < files[j].FileID
+	})
+
+	limit := query.Limit
+	if limit <= 0 || limit > len(files) {
+		limit = len(files)
+	}
+	return ListFilesResult{Files: files[:limit]}
+}
+
+func messageLooksFileBacked(message Message) bool {
+	return strings.Contains(strings.ToUpper(message.Subject), "FILE_TRANSFER") || extractMessageFileName(message.Text) != ""
+}
+
+func extractMessageFileName(text string) string {
+	match := fileNamePattern.FindString(strings.TrimSpace(text))
+	return strings.Trim(match, " .,;，。；")
+}
+
+func fileID(messageID string, fileName string) string {
+	if messageID == "" {
+		return fileName
+	}
+	return messageID + ":" + fileName
+}
+
+func fileMatchesQuery(file File, query ListFilesQuery) bool {
+	if query.ConversationID != "" && file.ConversationID != query.ConversationID {
+		return false
+	}
+	if query.MessageID != "" && file.MessageID != query.MessageID {
+		return false
+	}
+	if query.FileID != "" && file.FileID != query.FileID {
+		return false
+	}
+	nameQuery := strings.ToLower(strings.TrimSpace(query.NameContains))
+	if nameQuery != "" && !strings.Contains(strings.ToLower(file.FileName), nameQuery) {
+		return false
+	}
+	return true
+}
+
+func mimeTypeForFileName(name string) string {
+	switch strings.ToLower(filepath.Ext(name)) {
+	case ".doc":
+		return "application/msword"
+	case ".docx":
+		return "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+	case ".xls":
+		return "application/vnd.ms-excel"
+	case ".xlsx":
+		return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+	case ".ppt":
+		return "application/vnd.ms-powerpoint"
+	case ".pptx":
+		return "application/vnd.openxmlformats-officedocument.presentationml.presentation"
+	case ".pdf":
+		return "application/pdf"
+	case ".zip":
+		return "application/zip"
+	case ".rar":
+		return "application/vnd.rar"
+	case ".png":
+		return "image/png"
+	case ".jpg", ".jpeg":
+		return "image/jpeg"
+	case ".txt":
+		return "text/plain"
+	case ".csv":
+		return "text/csv"
+	default:
+		return ""
+	}
+}

internal/isphere/files_test.go

@@ -0,0 +1,31 @@
+package isphere
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestListFilesFromMessagesExtractsFileTransferCandidates(t *testing.T) {
+	messages := []Message{
+		{ID: "msg-1", ConversationID: "alice@imopenfire1-lanzhou|bob@imopenfire1-lanzhou", Text: "redacted-report.docx", Timestamp: "1783423807000", Subject: "FILE_TRANSFER_CANCEL"},
+		{ID: "msg-2", ConversationID: "alice@imopenfire1-lanzhou|bob@imopenfire1-lanzhou", Text: "plain chat", Timestamp: "1783423808000"},
+		{ID: "msg-3", ConversationID: "room@conference.imopenfire1-lanzhou", Text: "redacted-screenshot.png", Timestamp: "1783423809000"},
+	}
+
+	got := ListFilesFromMessages(messages, ListFilesQuery{NameContains: "report", Limit: 10})
+	want := ListFilesResult{Files: []File{
+		{
+			FileID:         "msg-1:redacted-report.docx",
+			MessageID:      "msg-1",
+			ConversationID: "alice@imopenfire1-lanzhou|bob@imopenfire1-lanzhou",
+			FileName:       "redacted-report.docx",
+			MimeType:       "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+			CreatedAt:      "1783423807000",
+			Source:         "local_readonly",
+			RawRef:         "packetlog_file_transfer",
+		},
+	}}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("ListFilesFromMessages() = %#v, want %#v", got, want)
+	}
+}