feat(conversation): add conversation list command (#35)

* docs(thread): document group IDs in --notify help text

`tdc thread reply/create --notify` already accepts custom group IDs
(partitioned via resolveNotifyIds → groups), but the help text only
mentioned "user IDs". Since Comms group IDs are non-numeric base58
strings that look nothing like user IDs, the capability was effectively
undiscoverable from --help. Mention groups in both option descriptions
and add a group-notify example to the reply command's existing example
block (alongside --close / --file).

No behaviour change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(skill): sync SKILL_CONTENT --notify examples with group support

Per AGENTS.md, src/lib/skills/content.ts must track command-description and
example changes. The reply/create --notify examples said "users" only; make
them mention groups and add a group-notify example (base58 group ID next to a
numeric user ID). Regenerated skills/comms-cli/SKILL.md via `sync:skill`;
check:skill-sync passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat(conversation): add conversation list command

List DMs and group conversations filtered by participant, name, or kind.
Reuses the existing plumbing: getAllConversations becomes
getConversationsByState(state), and listConversationsWithUser becomes the
shared renderConversationList. Defaults to active conversations; --state
opts into archived. SKILL_CONTENT and README updated, SKILL.md regenerated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(conversation): address list review feedback

Three doistbot P2s on the conversation list command:
- Resolve --participant against the full roster (includeRemoved) so a
  participant who has left the workspace still matches; the renderer already
  shows removed participants, and archived DMs often include them.
- Resolve participants and fetch conversations concurrently (Promise.all)
  rather than sequentially — they're independent once the workspace is known.
- Skip the workspace-wide user-map fetch for --json/--ndjson without --full,
  where participantNames are filtered back out anyway (also speeds up
  conversation with machine output, which shares the renderer).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lmjabreu

README.md

@@ -124,6 +124,7 @@ tdc thread reply <ref>              # reply to a thread
 tdc thread rename <ref> "New title" # rename a thread
 tdc thread update <ref> "New body"  # edit a thread's body (first post)
 tdc conversation unread             # list unread conversations
+tdc conversation list               # list conversations (--kind, --participant, --name, --state)
 tdc conversation view <ref>         # view conversation messages
 tdc msg view <ref>                  # view a conversation message
 tdc search "keyword"                # search across workspace

skills/comms-cli/SKILL.md

@@ -154,6 +154,14 @@ tdc comment delete <comment-ref> --yes --json        # Delete and return status
 
 ```bash
 tdc conversation unread                    # List unread conversations
+tdc conversation list                      # List active conversations (DMs and groups)
+tdc conversation list --kind group         # Only group conversations (3+ people)
+tdc conversation list --kind direct        # Only 1:1 conversations (and your self-DM)
+tdc conversation list --participant "Jane" # Only conversations including these users (comma-separated)
+tdc conversation list --name "release"     # Filter by title substring (case-insensitive)
+tdc conversation list --state archived     # Archived conversations only (active|all|archived; default active)
+tdc conversation list --snippet            # Include the latest message snippet
+tdc conversation list --limit 20 --json    # Cap rows and output as JSON
 tdc conversation <conversation-ref>        # View conversation (shorthand for view)
 tdc conversation view <conversation-ref>   # View conversation messages
 tdc conversation with <user-ref>           # Find your 1:1 DM with a user
@@ -430,6 +438,7 @@ tdc thread view <thread-id>
 **Check DMs:**
 ```bash
 tdc conversation unread --json
+tdc conversation list --kind group --json     # find a group DM by participants/name
 tdc conversation view <conversation-id>
 tdc conversation with "Alice Example"
 tdc conversation reply <id> "Got it, thanks!"