Let the host fit extension header rows

Return inventory entries as styled text chunks and remove the extension's
byte-counting wrapper. The host now owns display-width measurement,
wrapping and padding for these rows.

1 files changed, 57 insertions, 2 deletions

diff --git a/spec/test_init.lua b/spec/test_init.lua
index e3b4d55..a9956c4 100644
--- a/spec/test_init.lua
+++ b/spec/test_init.lua
@@ -138,8 +138,13 @@ return {
         assert(not plain:find("unusable", 1, true), "invalid workflows stay out of the usable inventory")
         assert(handle.commands_by_name["workflow:unusable"] == nil,
             "the header inventory matches command registration")
-        assert(rendered[#rendered] == "", "annotations stay before the trailing blank")
-        assert(#rendered > 4, "inventories wrap at the component width")
+        assert(rendered[1] == "Panto", "inner component output stays first")
+        assert(rendered[2] == "\27[2m subagents: reviewer\27[0m",
+            "the profile inventory stays one styled text chunk")
+        assert(rendered[3] == "\27[2m workflows: review-chain\27[0m",
+            "the workflow inventory follows the profile inventory")
+        assert(rendered[4] == "", "annotations stay before the trailing blank")
+        assert(#rendered == 4, "header injection does not hand-roll wrapped rows")
 
         local primary_messages = handle.ext.agent:conversation():messages()
         local guidance = primary_messages[#primary_messages].blocks[1].text
@@ -150,6 +155,56 @@ return {
         has(guidance, "Do not actively wait or poll with `sleep`")
     end },
 
+    { "the header injects both inventories verbatim, in order, style-isolated", function()
+        -- Phase 4 of the row-normalization plan deletes the extension's own
+        -- wrapping. What the extension still owns is the ORDER of the two
+        -- inventories, the insertion point, style isolation (each chunk resets
+        -- itself so nothing leaks into the host's rows), and handing names over
+        -- byte-intact so Engine.fit measures the real display width.
+        local header
+        activate_bare(function(handle, ok, err)
+            assert(ok, tostring(err))
+            -- No trailing blank line from the inner component: this exercises
+            -- the append-at-the-end branch of the insertion point, which the
+            -- other header case (with a trailing blank) does not.
+            handle.emit("session_start", {
+                get_component = function()
+                    return { render = function() return { "Panto" } end }
+                end,
+                set_component = function(_, component)
+                    header = component
+                end,
+            })
+        end)
+        assert(header, "session_start must wrap the header component")
+
+        -- The extension performs no string processing on the names beyond a
+        -- `table.concat`, and reacts to `width` only by forwarding it to the
+        -- inner component. Rendering at an absurdly narrow width and at a wide
+        -- one must therefore be byte-identical: that is what guarantees long
+        -- and non-ASCII profile/workflow names reach Engine.fit intact.
+        local narrow = header:render(1)
+        local wide = header:render(500)
+        assert(#narrow == 3, "expected 3 chunks (inner + two inventories), saw " .. #narrow)
+        for index = 1, #narrow do
+            assert(narrow[index] == wide[index],
+                "the header must not depend on width; chunk " .. index .. " differed")
+        end
+
+        assert(narrow[1] == "Panto", "the inner component's output stays first")
+        local subagents = narrow[2]:match("^\27%[2m subagents: (.*)\27%[0m$")
+        local workflows = narrow[3]:match("^\27%[2m workflows: (.*)\27%[0m$")
+        assert(subagents, "chunk 2 is the profile inventory: " .. narrow[2])
+        assert(workflows, "chunk 3 is the workflow inventory: " .. narrow[3])
+
+        for _, chunk in ipairs({ narrow[2], narrow[3] }) do
+            assert(chunk:sub(1, 4) == "\27[2m", "each inventory chunk opens its own style")
+            assert(chunk:sub(-4) == "\27[0m", "each inventory chunk resets, so styles cannot leak")
+            assert(not chunk:find("\n", 1, true), "the extension emits no rows of its own")
+            assert(not chunk:find("\226\128\166"), "the extension truncates nothing")
+        end
+    end },
+
     { "layered config sets max_concurrent with later layers winning", function()
         local tmp = os.tmpname()
         os.remove(tmp)