docs: update filesystem spec to match current implementation (cfg, remove stale files)

doc/MULTI_AGENT.md

@@ -13,10 +13,9 @@ Every session lives under `/s/{id}/`:
 | `/s/new` | Create a session (write `name`, `backend`, `model`, `agent`, `cwd`) |
 | `/s/{id}/prompt` | Submit a prompt (dispatched async on close) |
 | `/s/{id}/chat` | Cumulative conversation history (append-only read) |
-| `/s/{id}/state` | Current state: `idle`, `thinking`, `calling:<tool>` |
+| `/s/{id}/cfg` | Session config (KV): state, backend, model, agent, cwd, params |
 | `/s/{id}/statewait` | **Blocking read** — returns when state changes |
-| `/s/{id}/ctl` | Control commands: `stop`, `kill`, `compact`, model/backend switches |
-| `/s/{id}/cfg` | Mutable session config (KV pairs) |
+| `/s/{id}/ctl` | Control commands: `stop`, `kill`, `compact`, `rn <name>` |
 
 Utility files at the session root (`/s/`) provide higher-level operations:
 

doc/USAGE.md

@@ -135,7 +135,7 @@ Schedule regular cleanup with a cron job:
 ```sh
 cat $OLLIE/s/new                           # show the spec template
 printf 'cwd=%s\n---\nSummarize this.\n' "$PWD" > $OLLIE/s/new
-cat $OLLIE/s/<session-id>/state            # running | idle | failed: <reason>
+cat $OLLIE/s/<session-id>/cfg              # state, backend, model, agent, cwd, params
 cat $OLLIE/s/<session-id>/chat
 rm -r $OLLIE/s/<session-id>               # cancel and remove
 ```
@@ -288,10 +288,10 @@ send() {
     while true; do
         read -r _ <&3 && { exec 3<&-; break; }
         exec 3<&-
-        [ "$(cat s/$sid/state)" != "idle" ] && break
+        [ "$(awk -F= '/^state=/{print $2}' s/$sid/cfg)" != "idle" ] && break
         exec 3< s/$sid/statewait
     done
-    until [ "$(cat s/$sid/state)" = "idle" ]; do sleep 0.5; done
+    until [ "$(awk -F= '/^state=/{print $2}' s/$sid/cfg)" = "idle" ]; do sleep 0.5; done
     tail -c +$(($(cat s/$sid/offset) + 1)) s/$sid/chat
 }
 

doc/help.md

@@ -21,7 +21,6 @@ ollie/
   backends        available backends (ro)    cat
   help            this file (ro)             cat
   m/              memories (r/w)             ls, cat, edit
-    idx           memory index (ro)          cat
   p/              prompt templates (ro)      ls, cat
   s/              sessions                   ls
     idx           session index (ro)         cat: id state cwd backend model, one per line
@@ -34,25 +33,24 @@ ollie/
     bbg           background query (x)       exec s/bbg [flags] [prompt...]
     cleanup       kill idle sessions (x)     exec s/cleanup
     <id>/         session directory          rm -r to kill; mv to rename
-      agent       active agent (r/w)
-      backend     active backend (r/w)
+      cfg         session config (r/w)       cat: KV (state, backend, model, agent, cwd, maxTokens, temperature, frequencyPenalty, presencePenalty); write KV to change
       chat        conversation log (r/w; write to save transcript to tr/)
-      offset      byte offset of chat after last user prompt; tail -c +$((offset+1)) gives model response (ro)
+      context     rendered context window (ro)
+      cost        estimated cost (ro)
       ctl         control (w)                stop, kill, clear, compact, rn <name>
       ctxsz       context size (ro)
-      ctxszwait   blocks until ctxsz changes (ro)
-      cwd         working directory (r/w)
-      cwdwait     blocks until cwd changes (ro)
+      env         session environment (ro)
       fifo.in     queue a prompt (w)
       fifo.out    pop queued prompt (ro)
-      model       active model (r/w)
       models      available models (ro)
+      offset      byte offset after last user prompt (ro)
+      plan        plan scratchpad (r/w)
       prompt      submit prompt (w)
-      state       agent state (ro)           idle | thinking | calling: <tool>
+      prompt.prev previous prompt (ro)
       statewait   blocks until state changes (ro)
       systemprompt rendered system prompt (ro)
+      tail        tail helper (x)
       usage       token counts (ro)
-      usagewait   blocks until usage changes (ro)
   sk/             skills (r/w)               ls, cat, edit
     idx           skill index (ro)           cat
     <name>.md     skill content (r/w)
@@ -60,6 +58,9 @@ ollie/
     idx           tool index (ro)            cat
   tr/             transcripts (ro)           ls, cat
     <YYYYMMddTHHmmss>-chat.md  saved transcripts
+  u/              utility scripts (x)        ls, exec
+  x/              system scripts (x)         ls, exec
+  tmp/            scratch space (r/w)        ls, cat, edit, rm
 ```
 
 ## Session management
@@ -76,12 +77,12 @@ echo stop > ~/mnt/ollie/s/<id>/ctl                   # interrupt current turn
 ```sh
 cat ~/mnt/ollie/backends                             # list backends
 cat ~/mnt/ollie/s/<id>/models                        # list models for current backend
-echo ollama > ~/mnt/ollie/s/<id>/backend
-echo qwen3:8b > ~/mnt/ollie/s/<id>/model
-echo myagent > ~/mnt/ollie/s/<id>/agent
+echo backend=ollama > ~/mnt/ollie/s/<id>/cfg
+echo model=qwen3:8b > ~/mnt/ollie/s/<id>/cfg
+echo agent=myagent > ~/mnt/ollie/s/<id>/cfg
 ```
 
-Writes to backend, model, and agent are rejected while the agent is running.
+Writes to cfg are rejected while the agent is running.
 
 ## Environment