repl: session persistence wiring — auto-log, :save, :resume, :sessions

Phase 1 session log integration per PHASE1.md §6.

On every M.run(), open a session file at
  <config.history.dir>/sessions/<utc-iso8601>.jsonl
with a meta header (started, model, aish_version). If history.dir is
unset or unwritable, status-log the disable and continue without
persistence.

ask_ai logs the merged user turn (after pending exec output is folded
in) and the assistant turn (after streaming completes). run_shell does
NOT log [exec output] — that becomes part of the next user turn when
ctx.pending_exec_output is flushed.

New meta commands:
  :sessions       list session files; "*" marks the active one
  :save <name>    rename current session log to <name>.jsonl (auto-
                  appends .jsonl); reopens for continued append
  :resume <name>  load <name>.jsonl into ctx (replaces current turns
                  via ctx:reset + append loop). The current process's
                  own session log is unaffected — Phase 1 chooses
                  per-process logs over chained continuations.

:quit and EOF (Ctrl-D) both close the session file via shutdown_session
before exiting.

HELP text updated (no longer "Phase 0:" header since meta set has
grown). Q15 noted in PHASE1.md §10 (resume into non-empty context) is
resolved by the ctx:reset() in :resume — silent overwrite for Phase 1,
revisit if anyone cares.

End-to-end live verified: chat -> auto-log; :save renames; :sessions
listings; :resume + :history shows the round-trip.

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

repl.lua

@@ -8,12 +8,13 @@ local executor = require("executor")
 local broker   = require("broker")
 local renderer = require("renderer")
 local Context  = require("context")
+local history  = require("history")
 
 local M = {}
 
 local HELP = [[
-Meta commands (Phase 0):
-  :quit / :q       exit aish
+Meta commands:
+  :quit / :q       exit aish (current session is flushed and closed)
   :clear           clear screen (history kept)
   :reset           clear in-memory conversation history
   :model <name>    switch active model
@@ -21,6 +22,9 @@ Meta commands (Phase 0):
   :history         show conversation turns
   :exec <cmd>      force shell execution
   :ask <text>      force AI query
+  :sessions        list session log files
+  :save <name>     rename current session log to <name>.jsonl
+  :resume <name>   load <name>.jsonl turns into the in-memory context
   :help            this message
 ]]
 
@@ -35,6 +39,30 @@ function M.run(config)
 
     local ctx = Context.new(config.context or {})
 
+    -- Session log (PHASE1.md §6). Always open one on startup; auto-write
+    -- every user/assistant turn; close on :quit. If history.dir is set but
+    -- unwritable, log a status and continue without persistence.
+    local history_dir   = (config.history and config.history.dir) or nil
+    local sessions_dir  = history_dir and (history_dir .. "/sessions") or nil
+    local session_path  = sessions_dir
+        and (sessions_dir .. "/" .. os.date("!%Y-%m-%dT%H-%M-%SZ") .. ".jsonl")
+    local session
+    if session_path then
+        local sess, serr = history.open(session_path, {
+            started      = os.date("!%Y-%m-%dT%H:%M:%SZ"),
+            model        = active_name,
+            aish_version = "phase1",
+        })
+        if sess then
+            session = sess
+        else
+            renderer.status("session log disabled: " .. tostring(serr))
+        end
+    end
+    local function log_turn(turn)
+        if session then session:append(turn) end
+    end
+
     local function prompt()
         return ("[aish:%s]> "):format(active_name)
     end
@@ -74,6 +102,7 @@ function M.run(config)
     local function ask_ai(text)
         local prev_pending = ctx.pending_exec_output
         ctx:append_user(text)  -- flushes any pending [exec output] as prefix
+        log_turn(ctx.turns[#ctx.turns])  -- merged user turn (may include exec)
 
         local parts = {}
         local ok, err = broker.chat_stream(active_cfg, ctx:to_messages(),
@@ -91,6 +120,7 @@ function M.run(config)
         end
         local resp = table.concat(parts)
         ctx:append({ role = "assistant", content = resp })
+        log_turn(ctx.turns[#ctx.turns])
         status_evictions(ctx:enforce_budget())
 
         for _, cmd in ipairs(executor.extract_cmd_lines(resp)) do
@@ -105,10 +135,14 @@ function M.run(config)
         end
     end
 
+    local function shutdown_session()
+        if session then session:close(); session = nil end
+    end
+
     -- Meta dispatch table.
     local meta = {
-        quit  = function() os.exit(0) end,
-        q     = function() os.exit(0) end,
+        quit  = function() shutdown_session(); os.exit(0) end,
+        q     = function() shutdown_session(); os.exit(0) end,
         clear = function() io.write("\27[H\27[2J"); io.flush() end,
         reset = function()
             ctx:reset(); renderer.status("context reset")
@@ -149,6 +183,56 @@ function M.run(config)
             if args == "" then renderer.status("usage: :ask <text>"); return end
             ask_ai(args)
         end,
+        sessions = function()
+            if not sessions_dir then renderer.status("(no history.dir configured)"); return end
+            local names = history.list_sessions(sessions_dir)
+            if #names == 0 then renderer.status("(no sessions in " .. sessions_dir .. ")"); return end
+            for _, n in ipairs(names) do
+                local mark = (session_path and session_path:match("[^/]+$") == n)
+                             and "*" or " "
+                io.write(("  %s %s\n"):format(mark, n))
+            end
+        end,
+        save = function(args)
+            local name = args:match("^%s*(%S+)")
+            if not name then renderer.status("usage: :save <name>"); return end
+            if not (session and session_path and sessions_dir) then
+                renderer.status("no active session to save")
+                return
+            end
+            name = name:gsub("%.jsonl$", "")
+            local new_path = sessions_dir .. "/" .. name .. ".jsonl"
+            if new_path == session_path then
+                renderer.status("already named " .. name)
+                return
+            end
+            session:close()
+            local ok, rerr = os.rename(session_path, new_path)
+            if not ok then
+                renderer.status("rename failed: " .. tostring(rerr))
+                -- best-effort reopen of original path so logging continues
+                session = history.open(session_path)
+                return
+            end
+            session_path = new_path
+            session = history.open(session_path)  -- reopen for continued append
+            renderer.status("saved as " .. name .. ".jsonl")
+        end,
+        resume = function(args)
+            local name = args:match("^%s*(%S+)")
+            if not name then renderer.status("usage: :resume <name>"); return end
+            if not sessions_dir then renderer.status("(no history.dir configured)"); return end
+            name = name:gsub("%.jsonl$", "")
+            local path = sessions_dir .. "/" .. name .. ".jsonl"
+            local meta_hdr, turns = history.load(path)
+            if not (meta_hdr or turns) then
+                renderer.status("resume failed: cannot load " .. path)
+                return
+            end
+            ctx:reset()
+            for _, t in ipairs(turns or {}) do ctx:append(t) end
+            renderer.status(("resumed %d turns from %s"):format(#(turns or {}), name))
+        end,
         help = function() io.write(HELP) end,
     }
 
@@ -156,7 +240,9 @@ function M.run(config)
     while true do
         local line = rl.readline(prompt())
         if line == nil then          -- EOF (Ctrl-D on empty line)
-            io.write("\n"); break
+            io.write("\n")
+            shutdown_session()
+            break
         end
         if line:gsub("%s", "") == "" then
             -- empty / whitespace-only: skip silently