feat(bitrix24): imbot.v2 migration, 2-way media, openline sender-tag echo, and hardening (#1236)

* refactor(bitrix24): rename "Path B" framing to maintainer-specified naming [B24:2794]

Per maintainer hard rule #10 (no generic "Path A/B" framing) from PR #1061
review. The Bitrix24 MCP auto-onboard flow is Bitrix-specific glue
("Bitrix24 OAuth -> existing mcp_user_credentials bridge"), NOT a generic
MCP architecture pattern.

Naming convention applied consistently:
- First mention per file: full "Bitrix24 OAuth -> existing
  mcp_user_credentials bridge" (matches maintainer comment verbatim).
- Subsequent mentions in same file: shortened "mcp_user_credentials bridge".
- Test/log context referencing literal endpoint /api/auto-onboard: keep
  "auto-onboard" reference (it's the actual API endpoint name).

Changes are documentation-only:
- Rename in code comments + test descriptions + plan docs.
- Clarify framing in mcp_client.go + provisioner.go doc comments to
  emphasize Bitrix-specific glue (not generic MCP infra).
- Reuse existing mcp_user_credentials table + MCPServerStore methods
  (no schema / store / abstraction change).

Files:
- cmd/gateway.go (factory registration doc)
- internal/channels/bitrix24/{channel,factory,mcp_client,provisioner}.go
- internal/channels/bitrix24/{mcp_client,provisioner}_test.go
- plan/goclaw-mcp-integration.md (21 occurrences)

Verified: go build + MCP-related tests pass (TestProvision*,
TestInitMCPProvisioner*, TestMCPClient*).

Phase 1 of Path C execution per
plans/reports/decision-log-260519-1555-bitrix24-pr-fork-decision.md.

* fix: confine outbound media paths to agent workspace [B24:2794]

Tool MEDIA:<path> output reached channel file-upload sinks (Bitrix
imbot.v2.File.upload, Telegram sendDocument, etc.) verbatim via
parseMediaResult, with no workspace-boundary check. A malicious or buggy
tool emitting MEDIA:/etc/passwd could exfiltrate arbitrary files to chat.

Extract the EvalSymlinks+Rel containment from extractMediaFromContent into
a shared confineToWorkspace helper and apply it at the parseMediaResult
sink in processToolResult. Fixing at the source/egress boundary protects
every channel at once rather than per-channel. Paths that escape the
workspace are dropped and logged (security.media_path_rejected).

Add TestConfineToWorkspace (boundary unit) and
TestParseMediaResultConfinedToWorkspace (sink regression for H2).

* feat(bitrix24): support inbound + outbound media via imbot.v2 File API [B24:2794]

Bitrix24 channel was text-only; attachments were parsed but dropped.
- Inbound: download chat files via imbot.v2.File.download (one-time URL),
  forward to the agent with MIME preserved (internal/channels/bitrix24/download.go).
- Outbound: upload agent media to the chat via imbot.v2.File.upload
  (internal/channels/bitrix24/send_media.go).
- Add BaseChannel.HandleMessageMedia to preserve MIME/filename through the bus.
- Per-channel media_max_mb cap (default 20) applies to both directions.

Tests: 92 pass (internal/channels/bitrix24 + internal/channels), go vet clean (PG + sqliteonly).

* refactor(bitrix24): migrate messaging/bot-list/unregister to imbot v2 API [B24:2794]

Move outbound REST calls to the imbot v2 family (keeps register on v1):
- imbot.message.add -> imbot.v2.Chat.Message.send (fields.message shape, live-verified)
- imbot.bot.list (+ legacy imbot.list fallback) -> imbot.v2.Bot.list; add botListRows
  to normalize the v2 {bots:[...]} envelope, legacy array, and id-keyed map forms
- imbot.unregister -> imbot.v2.Bot.unregister

Bot registration stays on v1 imbot.register: v2 imbot.v2.Bot.register changes the
event-delivery model (per-event handler URLs -> eventMode), which would require
rewriting the inbound event parser. No user-facing behavior change.

Tests: bitrix24 package green; go vet ./... clean.

* feat(bitrix24): route whisper via v1 SKIP_CONNECTOR + add v2 replyId [B24:2794]

Bot was leaking HiddenMessage (whisper) replies to the external Zalo
connector because every outbound call went through imbot.v2.Chat.Message.send,
which has no equivalent of the v1 SKIP_CONNECTOR flag. Branch the outbound
path on inbound visibility:

  whisper → imbot.message.add + SKIP_CONNECTOR=Y  (v1, send_v1.go)
  public  → imbot.v2.Chat.Message.send + fields.replyId  (v2, send_v2.go)

Pipeline:
  events.go        parse data[PARAMS][PARAMS][COMPONENT_ID]=HiddenMessage
                   into EventParams.IsHiddenMessage (form + JSON variants)
  handle.go        set bitrix_visibility on InboundMessage.Metadata
  consumer         forward visibility + message_id into OutboundMessage
  send.go          resolveSendOptions + sendChunk dispatcher +
                   shared callWithRateLimitRetry helper
  metadata_keys.go single source of truth for the keys + values

Defaults preserve pre-refactor behaviour: callers that don't populate
bitrix_visibility still go through v2 public, and replyId is omitted
unless a numeric bitrix_message_id arrives in metadata.

Tests:
  TestParseEvent_FormURLEncoded_IsHiddenMessage  (3 cases)
  TestParseEvent_JSON_IsHiddenMessage             (3 cases)
  TestResolveSendOptions                          (8 cases)
  TestSend_BranchesOnVisibility                   (4 cases)

* feat(bitrix24): openline sender-tag echo on replies [B24:2794]

Openline sender-tag echo (this change):
- Capture the connector sender tag ("[name #id]:" or "[name] #id:") from
  inbound openline group messages, strip it from the body the agent sees,
  and re-prepend the canonical "[name] #id:" form to the reply so the Open
  Channel connector routes the answer back to the right external user.
- New sender_prefix.go helper (+ test) accepts both inbound layouts and
  emits one canonical form; scoped to messages carrying the tag, so plain
  chats are unaffected.
- metadata_keys.go: MetaKeySenderPrefix; handle.go capture/strip/stash;
  gateway_consumer_normal.go forwards the key; send.go prepends it on the
  first chunk before chunking.

Bundled bitrix24 channel-core work already on this branch:
- handle.go: @mention is the sole trigger for both staff and connector
  customers; unmentioned traffic is dropped (was: drop all connector msgs).
- isGroupMessageType: treat SONET_GROUP "B" as a group.
- handle_test.go, mcp_client_test.go: cover the above.

* feat(bitrix24): accept colon-less openline sender tag, echo [name] #id [B24:2794]

The Open Channel connector dropped the trailing colon from its sender tag:
inbound now arrives as "[Name] #id <msg>" (was "[Name] #id: <msg>"). The
id-bearing patterns required the colon, so the tag fell through to the
name-only branch and the reply echoed "[Name]" — dropping the #id the
connector needs to route the answer back.

- sender_prefix.go: make the trailing ":" optional on both id layouts
  ([name #id] / [name] #id, with or without colon) and echo the canonical
  "[name] #id" (no colon) to match the connector's current format. Bare
  "[name]" (no id) still echoes "[name]" for Open Channel only.
- handle.go: gate the bare name-only layout to Open Channel (isOpenChannel)
  so ordinary group chats starting with "[x] ..." are left untouched.
- sender_prefix_test.go: cover colon/no-colon x id-inside/id-outside, the
  name-only openline case, and the non-openline no-op.

* fix: security and robustness fixes from the bitrix24 channel review [B24:2794]

- download.go: block redirect-based SSRF on inbound media. CheckRedirect
  re-validates each hop (http(s) only, reject private/loopback/link-local
  hosts, cap hops); the initial portal-domain pin is no longer bypassable
  via a 3xx to an internal service. Public-host redirects still allowed.
- handle.go: extract/echo the openline sender tag only for Open Channel
  sessions (was: any group chat), removing bogus prefixes in CRM group
  chats and narrowing the forged-tag misroute surface.
- loop_tools.go + loop_media.go: confine result.Media to the agent / team /
  tenant-allowed roots (new confineToAnyRoot) before a channel uploads it,
  so a prompt-injected out-of-workspace path (e.g. /etc/passwd) cannot
  exfiltrate, while legitimate cross-workspace media (team files, delegatee
  output) still flows.
- send_media.go: bounded outbound read via io.LimitReader replaces the
  os.Stat + os.ReadFile pair, closing the TOCTOU size-cap bypass; cap a
  single message's outbound attachments at 10 (mirrors inbound).
- register.go: paginate imbot.v2.Bot.list (limit/offset + hasNextPage,
  capped at 40 pages) so verify/lookup see bots past the first 50.
- mcp_client.go: redact access_token / refresh_token / client_secret from an
  echoed MCP error body before it is logged or returned (+ test).

* fix(security): validate resolved dial IP on Bitrix media redirects [B24:2794]

The inbound media download redirect guard only string-checked the redirect
hostname (isPrivateOrLoopback on req.URL.Hostname()), so a redirect to a public
hostname that resolves to 127.0.0.1 / 169.254.169.254 / an RFC1918 address — or a
DNS-rebinding swap between check and dial — still passed the guard and the client
would connect. Reported in PR review.

Add security.NewRedirectFollowingSafeClient: it follows redirects but validates
the RESOLVED destination IP of every hop at dial time via net.Dialer.Control,
reusing the existing blocked-CIDR list. The IP it checks is the IP actually
dialed, so both redirect-to-internal and DNS rebinding are refused, while
legitimate public CDN redirects still succeed. download.go now uses it instead of
the hostname-string guard.

Tests: deterministic dial-control table (loopback / link-local / private /
multicast / unspecified / public, v4 + v6), malformed/non-IP addr, test bypass,
loopback-dial-blocked client wiring, and redirect cap + scheme checks.

* feat(bitrix24): per-participant Zalo openline identity from 3-token sender tag [B24:2794]

Parse the connector's "[Name] #uid #msgId" sender tag so each external
customer in a shared Open Channel group gets its own contact + USER.md
instead of collapsing onto the connector proxy id. Identity minting is
gated on IS_CONNECTOR=Y to reject operator forged tags. Echo back the
msgId only ("#msgId") on replies; keep the legacy single-number and
name-only layouts unchanged. Zero DB migration.

- sender_prefix.go: parseOpenlineSenderTag() classifies 3-token / legacy / name-only
- handle.go: synthetic senderID "openlines:{instance}:{chat}:{uid}" + participant_user_id metadata, gated on FromIsConnector
- gateway_consumer_normal.go: deriveGroupUserID() routes participant -> per-person scope, group fallback otherwise
- send.go: buildAddressMention numeric-id guard so synthetic ids don't emit invalid [USER=...] BBCode
- MetaKeyMessageID kept as Bitrix MESSAGE_ID (drives v2 fields.replyId); connector msgId surfaced only via echo prefix

---------

Co-authored-by: DangTinh311 <dangtinh31193@gmail.com>
Co-authored-by: Chinh Dang <chinhdang@192.168.68.104>

docs/05-channels-messaging.md

@@ -234,22 +234,22 @@ flowchart TD
 
 ## 4. Channel Comparison
 
-| Feature | Telegram | Feishu/Lark | Discord | Slack | WhatsApp | Zalo OA | Zalo Personal |
-|---------|----------|-------------|---------|-------|----------|---------|---------------|
-| Connection | Long polling | WS (default) / Webhook | Gateway events | Socket Mode | Direct protocol (in-process) | Long polling | Internal protocol |
-| DM support | Yes | Yes | Yes | Yes | Yes | Yes (DM only) | Yes |
-| Group support | Yes (mention gating) | Yes | Yes | Yes (mention gating + thread cache) | Yes | No | Yes |
-| Forum/Topics | Yes (per-topic config) | Yes (topic session mode) | -- | -- | -- | -- | -- |
-| Message limit | 4,096 chars | Configurable (default 4,000) | 2,000 chars | 4,000 chars | WhatsApp native limit | 2,000 chars | 2,000 chars |
-| Streaming | Typing indicator | Streaming message cards | Edit "Thinking..." | Edit "Thinking..." (throttled 1s) | No | No | No |
-| Media | Photos, voice, files | Images, files (30 MB) | Files, embeds | Files (download w/ SSRF protection) | Images, audio, video, documents | Images (5 MB) | -- |
-| Speech-to-text | Yes (STT proxy) | -- | -- | -- | -- | -- | -- |
-| Voice routing | Yes (VoiceAgentID) | -- | -- | -- | -- | -- | -- |
-| Rich formatting | Markdown → HTML | Card messages | Markdown | Markdown → mrkdwn | Plain text | Plain text | Plain text |
-| Bot commands | 10+ commands | -- | -- | -- | -- | -- | -- |
-| Tool allow list | Per-topic | -- | -- | -- | -- | -- | -- |
-| Pairing support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
-| Status reactions | Yes | Yes | -- | Yes | -- | -- | -- |
+| Feature | Telegram | Feishu/Lark | Discord | Slack | WhatsApp | Zalo OA | Zalo Personal | Bitrix24 |
+|---------|----------|-------------|---------|-------|----------|---------|---------------|----------|
+| Connection | Long polling | WS (default) / Webhook | Gateway events | Socket Mode | Direct protocol (in-process) | Long polling | Internal protocol | Long polling (REST) |
+| DM support | Yes | Yes | Yes | Yes | Yes | Yes (DM only) | Yes | Yes |
+| Group support | Yes (mention gating) | Yes | Yes | Yes (mention gating + thread cache) | Yes | No | Yes | Yes |
+| Forum/Topics | Yes (per-topic config) | Yes (topic session mode) | -- | -- | -- | -- | -- | -- |
+| Message limit | 4,096 chars | Configurable (default 4,000) | 2,000 chars | 4,000 chars | WhatsApp native limit | 2,000 chars | 2,000 chars | 4,096 chars |
+| Streaming | Typing indicator | Streaming message cards | Edit "Thinking..." | Edit "Thinking..." (throttled 1s) | No | No | No | No |
+| Media | Photos, voice, files | Images, files (30 MB) | Files, embeds | Files (download w/ SSRF protection) | Images, audio, video, documents | Images (5 MB) | -- | Files (20 MB default) |
+| Speech-to-text | Yes (STT proxy) | -- | -- | -- | -- | -- | -- | -- |
+| Voice routing | Yes (VoiceAgentID) | -- | -- | -- | -- | -- | -- | -- |
+| Rich formatting | Markdown → HTML | Card messages | Markdown | Markdown → mrkdwn | Plain text | Plain text | Plain text | Plain text |
+| Bot commands | 10+ commands | -- | -- | -- | -- | -- | -- | -- |
+| Tool allow list | Per-topic | -- | -- | -- | -- | -- | -- | -- |
+| Pairing support | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
+| Status reactions | Yes | Yes | -- | Yes | -- | -- | -- | -- |
 
 ---
 
@@ -781,12 +781,53 @@ flowchart TD
 
 ---
 
+## 16. Bitrix24
+
+The Bitrix24 channel connects to a Bitrix24 portal via the `imbot.v2.*` REST API. Authentication uses an app token with `imbot` scope.
+
+### Key Behaviors
+
+- **Text limit**: 4,096 characters per message with automatic splitting at newlines
+- **Media support**: Both inbound and outbound file transfers with MIME preservation
+- **Default DM policy**: `"pairing"` (requires pairing code)
+- **Pairing debounce**: 60-second debounce on pairing instructions
+- **Media max size**: Configurable `media_max_mb` (default 20 MB) applies symmetrically to inbound downloads and outbound uploads
+
+### Inbound Media
+
+When a user sends a file to the bot:
+1. Resolve file metadata via `imbot.v2.File.download` → obtain one-time authenticated download URL
+2. Stream file to temp directory, preserving MIME type
+3. Forward to agent via `bus.MediaFile` with original filename
+4. Agent pipeline routes to appropriate reader (`read_image`, `read_document`, `read_audio`, `read_video`)
+
+**Configuration**: Size cap via `media_max_mb` (per `channel_instance` or config default). Oversized files are silently skipped (best-effort).
+
+### Outbound Media
+
+Agent-produced media files are uploaded to the chat via `imbot.v2.File.upload`:
+1. Read file from workspace
+2. Encode as base64
+3. POST to `imbot.v2.File.upload` with bot ID and chat ID
+4. Upload succeeds atomically: file is stored in portal Drive, attached to chat, and posted in a single REST call
+
+**Configuration**: Size cap via same `media_max_mb` knob (symmetric with inbound).
+
+### OAuth Scope
+
+The bot app must have the `imbot` scope granted. The `disk` scope is **not** required — all file operations are scoped to the message thread context.
+
+**Implementation**: `internal/channels/bitrix24/download.go` (inbound), `send_media.go` (outbound). New `BaseChannel.HandleMessageMedia()` method (in `internal/channels/channel.go`) centralizes media-aware message handling across all channels.
+
+---
+
 ## File Reference
 
 | Module | Path | Purpose |
 |---|---|---|
-| Channel core | `internal/channels/` | `Channel` interface, `BaseChannel`, `Manager` (StartAll/StopAll), outbound dispatcher, DB instance loader |
-| Platform adapters | `internal/channels/{telegram,feishu,discord,slack,whatsapp,zalo}/` | Per-platform: message handling, formatting, streaming, reactions, media, pairing |
+| Channel core | `internal/channels/` | `Channel` interface, `BaseChannel` (incl. `HandleMessageMedia()` method), `Manager` (StartAll/StopAll), outbound dispatcher, DB instance loader |
+| Platform adapters | `internal/channels/{telegram,feishu,discord,slack,whatsapp,zalo,bitrix24}/` | Per-platform: message handling, formatting, streaming, reactions, media, pairing |
+| Bitrix24 media | `internal/channels/bitrix24/download.go`, `send_media.go` | Inbound file download via `imbot.v2.File.download`, outbound upload via `imbot.v2.File.upload` |
 | Audio / STT | `internal/audio/` | Audio manager, STT chain resolution, legacy STT bridge |
 | Pairing & routing | `internal/store/pg/pairing.go`, `cmd/gateway_consumer.go` | Pairing code persistence, inbound message routing and cancel interception |