feat(agents): mcpctl chat REPL + agent CRUD + completions (Stage 5)

This is the moment the user can actually talk to an agent end-to-end:

  mcpctl create llm qwen3-thinking --type openai --model qwen3-thinking \
    --url http://litellm.nvidia-nim.svc.cluster.local:4000/v1 \
    --api-key-ref litellm-key/API_KEY
  mcpctl create agent reviewer --llm qwen3-thinking --project mcpctl-dev \
    --description "I review security design — ask me after each major change."
  mcpctl chat reviewer

Pieces:

* src/cli/src/commands/chat.ts (new) — REPL + one-shot. Streams the SSE
  endpoint and prints text deltas to stdout as they arrive; tool_call /
  tool_result events go to stderr in dim-style brackets so the chat
  output stays clean. LiteLLM-style flags (--temperature / --top-p /
  --top-k / --max-tokens / --seed / --stop / --allow-tool / --extra)
  layer over agent.defaultParams. In-REPL slash-commands: /set KEY VAL,
  /system <text>, /tools (list project's MCP servers), /clear (new
  thread), /save (PATCH agent.defaultParams = current overrides),
  /quit.

* src/cli/src/commands/create.ts — `create agent` mirroring the llm
  pattern. Every yaml-applyable field has a corresponding flag (memory
  rule); --default-temperature / --default-top-p / --default-top-k /
  --default-max-tokens / --default-seed / --default-stop /
  --default-extra / --default-params-file all populate agent.defaultParams.

* src/cli/src/commands/apply.ts — AgentSpecSchema accepts both `llm:
  qwen3-thinking` shorthand and `llm: { name: ... }` long form; runs
  after llms in the apply order so apiKey/llm references resolve. Round-
  trips with `get agent foo -o yaml | apply -f -` (memory rule).

* src/cli/src/commands/get.ts — agentColumns (NAME, LLM, PROJECT,
  DESCRIPTION, ID); RESOURCE_KIND mapping for yaml export.

* src/cli/src/commands/shared.ts — `agent`/`agents`/`thread`/`threads`
  added to RESOURCE_ALIASES.

* src/cli/src/index.ts — wires createChatCommand into the program; passes
  the resolved baseUrl + token so chat can stream SSE without going
  through ApiClient (which only does buffered request/response).

* completions/mcpctl.{fish,bash} regenerated. scripts/generate-completions.ts
  knows about agents (canonical + aliases) and emits a special-case
  `chat)` block that completes the first arg with `mcpctl get agents`
  names. tests/completions.test.ts: +9 new assertions covering agents in
  the resource list, chat in the commands list, --llm flag for create
  agent, agent-name completion for chat, etc.

CLI suite: 430/430 (was 421). Completions --check is clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/generate-completions.ts

@@ -184,7 +184,7 @@ async function extractTree(): Promise<CmdInfo> {
 // ============================================================
 
 const CANONICAL_RESOURCES = [
-  'servers', 'instances', 'secrets', 'secretbackends', 'llms', 'templates', 'projects',
+  'servers', 'instances', 'secrets', 'secretbackends', 'llms', 'agents', 'templates', 'projects',
   'users', 'groups', 'rbac', 'prompts', 'promptrequests',
   'serverattachments', 'proxymodels', 'all',
 ];
@@ -195,6 +195,7 @@ const ALIAS_ENTRIES: [string, string][] = [
   ['secret', 'secrets'], ['sec', 'secrets'],
   ['secretbackend', 'secretbackends'], ['sb', 'secretbackends'],
   ['llm', 'llms'], ['llms', 'llms'],
+  ['agent', 'agents'], ['agents', 'agents'],
   ['template', 'templates'], ['tpl', 'templates'],
   ['project', 'projects'], ['proj', 'projects'],
   ['user', 'users'],
@@ -904,6 +905,20 @@ function emitBashCase(emit: (s: string) => void, cmd: CmdInfo, root: CmdInfo): v
     return;
   }
 
+  // chat: first arg is agent name
+  if (name === 'chat') {
+    emit(`    ${name})`);
+    emit('      if [[ $((cword - subcmd_pos)) -eq 1 ]]; then');
+    emit('        local names');
+    emit('        names=$(_mcpctl_resource_names "agents")');
+    emit(`        COMPREPLY=($(compgen -W "$names ${optFlags}" -- "$cur"))`);
+    emit('      else');
+    emit(`        COMPREPLY=($(compgen -W "${optFlags}" -- "$cur"))`);
+    emit('      fi');
+    emit('      return ;;');
+    return;
+  }
+
   // console: first arg is project name
   if (name === 'console') {
     emit(`    ${name})`);