Bild: pipelined analyze→build architecture with multi-line UI

Implement STM-based pipeline that allows per-target progression
through build phases (analyze → wait for deps → build) with
concurrent workers.

Key changes: - TargetState enum tracks each target through pipeline
stages - Coordinator manages state, analyze queue, build queue
coordination - pipelineAnalysisWorker/pipelineBuildWorker pull from
queues concurrently - promoteWaiters unblocks targets when their
dependencies complete

UI improvements: - Multi-line mode reserves N lines for N targets,
updates in-place - Remove narrow terminal (<80 col) restriction for
multi-line mode - Add Skipped state with yellow [_] for non-buildable
files - Remove extra blank line at start of output

State symbols: [.] Pending, [+] Analyzing, [~] Building, [✓] Success
(green), [x] Failed (red), [_] Skipped (yellow)

1 files changed, 7 insertions, 3 deletions

diff --git a/Omni/Log/Concurrent.hs b/Omni/Log/Concurrent.hs
index 6dc7297..77131ef 100644
--- a/Omni/Log/Concurrent.hs
+++ b/Omni/Log/Concurrent.hs
@@ -20,13 +20,13 @@ import qualified Data.Text as Text
 import Omni.Log.Terminal (OutputMode (..), TerminalInfo (..), detectTerminal, truncateToWidth)
 import Omni.Namespace (Namespace)
 import qualified Omni.Namespace as Namespace
-import Rainbow (chunk, fore, green, red, white)
+import Rainbow (chunk, fore, green, red, white, yellow)
 import qualified Rainbow
 import qualified System.Console.ANSI as ANSI
 import qualified System.IO as IO
 import System.IO.Unsafe (unsafePerformIO)
 
-data BuildState = Analyzing | Pending | Building | Success | Failed
+data BuildState = Analyzing | Pending | Building | Success | Failed | Skipped
   deriving (Eq, Show)
 
 data LineManager = LineManager
@@ -88,7 +88,6 @@ withLineManager nss action = do
         MultiLine -> do
           -- Multi-line mode: reserve lines for each namespace
           let numLines = min (length nss) (tiHeight termInfo - 2)
-          IO.hPutStrLn IO.stderr ""
           replicateM_ numLines (IO.hPutStrLn IO.stderr "")
           withMVar terminalLock <| \_ -> ANSI.hCursorUp IO.stderr numLines
 
@@ -196,6 +195,7 @@ updateLineState ns buildState = do
             let (symbol, color) = case buildState of
                   Success -> ("✓", green)
                   Failed -> ("x", red)
+                  Skipped -> ("_", yellow)
                   Analyzing -> ("+", white)
                   Pending -> (".", white)
                   Building -> ("~", white)
@@ -211,6 +211,9 @@ updateLineState ns buildState = do
               Failed -> do
                 IO.hPutStrLn IO.stderr "" -- Keep failures visible
                 writeIORef lastOutputTransient False
+              Skipped -> do
+                IO.hPutStrLn IO.stderr "" -- Keep skipped visible
+                writeIORef lastOutputTransient False
               _ -> writeIORef lastOutputTransient True -- Transient states overwrite
             IO.hFlush IO.stderr
         MultiLine ->
@@ -229,6 +232,7 @@ updateLineState ns buildState = do
                 let (symbol, colorFn) = case buildState of
                       Success -> ("✓", fore green)
                       Failed -> ("x", fore red)
+                      Skipped -> ("_", fore yellow)
                       Analyzing -> ("+", identity)
                       Pending -> (".", identity)
                       Building -> ("~", identity)