Fix method-label reset, hello fixture state, and harness quoting.

em_reset cleared only one row of em_meth_label: ldx #$FF / dex / bpl exits
after the first store because $FE is negative. Method label ids from the count
pass survived into the emitting pass after fl_init had freed every flow label,
so a later fl_alloc could hand the same id to another label. The loop now
clears all 256 rows, and labels are stored as id + 1 so 0 means unassigned.

hello-test.s never cleared em_on. Since 5489ae6 added emitter BSS, em_on lands
on RAM that VICE's power-on pattern leaves non-zero, so the statement emitter
ran without print vectors and reported E227 at end program. The fixture now
clears em_on before parse_file, as every emitter caller must.

harness.tests.ps1 embedded quotes in arguments for the call operator, which
PowerShell 7.3+ escapes into the path; it now passes plain arguments and runs
under both Windows PowerShell 5.1 and PowerShell 7.

newLang/planning/claims/E04-S08.md

@@ -108,16 +108,34 @@ supply frame entry points keep their previous code shape (D156).
   `planning/epics-and-stories.md`, `planning/claims/E04-S08.md`.
 - Remaining risks: interface arguments and four-byte interface returns are not
   emitted (E06-S07); arguments are limited to `EM_ARG_MAX` (8) staged values;
-  the prologue's failure path returns without a diagnostic, so a refused frame
-  is currently silent; and the pre-existing `calls` suite failure described
-  below is unrelated but still red.
-
-## Known unrelated failure
-
-`calls` fails on a **fresh** build with `EM_ERR_LABEL` (7) and
-`FL_ERR_STATE` (3), `cg_len = 0x31`, while the same test passes when the build
-directory's older object files are reused. The identical signature reproduces
-on pristine `8a2d8ce` (verified by `git stash` + fresh `build/calls-test`), so
-it predates this story and points at emitter label state that is not
-deterministically initialized. It is not caused by E04-S08 and needs its own
-fix (initialize or validate the per-row method-label table before pass 2).
+  and the prologue's failure path returns without a diagnostic, so a refused
+  frame is currently silent.
+
+## Related label fix
+
+A fresh-build failure with `EM_ERR_LABEL` (7) and `FL_ERR_STATE` (3) reproduced
+on pristine `8a2d8ce` and was independent of this story. Its cause was the
+method-label table's `$FF` sentinel: any row whose byte was not `$FF` was taken
+as an already-assigned label 0, so a later method redefined it at a different
+offset. `em_reset` now clears the table to zero, `em_method_label` stores each
+label as `id + 1`, and a lookup outside 1..`FL_LABELS` allocates again. Fresh
+`calls` and `args` runs now pass.
+
+The clear loop itself was also wrong: `ldx #$FF` / `dex` / `bpl` stops after
+one row because `$FE` is negative, so ids from the count pass survived into the
+emitting pass after `fl_init` had freed every flow label. The loop now counts
+X up from 0 until it wraps, clearing all 256 rows on every `em_reset`.
+
+## Hello fixture regression
+
+`hello` failed at HEAD with `E227 CANNOT EMIT THIS CODE YET` at `end program`
+(verified passing at `221e0c5`, failing at `5489ae6`). `hello-test.s` never set
+`em_on`, and the new BSS variables moved it onto RAM that VICE's power-on
+pattern leaves non-zero, so the statement emitter ran without print vectors.
+The fixture now clears `em_on` before `parse_file`, as the emitter contract
+requires of every caller.
+
+The `parser` suite's verification passes, but its baseline hashes in
+`tests/regression/baseline.json` predate `221e0c5` and `5489ae6`; pristine
+HEAD's `parser-test.prg` already differs, so that entry needs a reviewed
+refresh.

newLang/src/compiler/emit.s

@@ -98,10 +98,11 @@ em_reset:
         sta em_n_routines
         lda #$FF
         sta em_loc_next
-        ldx #$FF
+        lda #$00                ; clear all 256 rows; X wraps $00 -> $00
+        tax
 @meth:  sta em_meth_label,x
-        dex
-        bpl @meth
+        inx
+        bne @meth
         lda #$02
         sta em_par_next
         rts
@@ -685,17 +686,24 @@ em_method_label:
         sta em_nid
         tax
         lda em_meth_label,x
-        cmp #$FF
-        bne @have
-        lda em_nid
+        beq @alloc
+        cmp #FL_LABELS + 1
+        bcs @alloc
+        sec
+        sbc #$01
+        tax
+        clc
+        rts
+@alloc: lda em_nid
         jsr fl_alloc
         bcs @bad
         ldy em_nid
         sta em_meth_label,y
         tax
+        lda em_meth_label,y
         clc
-        rts
-@have:  tax
+        adc #$01
+        sta em_meth_label,y
         clc
         rts
 @bad:   lda #EM_ERR_LABEL

newLang/tests/compiler/hello-test.s

@@ -27,6 +27,7 @@
 .import out_byte, out_bytes, out_finish, out_abort
 .import out_load, out_entry, out_start, out_err
 .import gen_stub
+.import em_on
 
 ; A conditional branch to a far error path: near branch over an absolute JMP.
 .macro ON_CARRY target
@@ -104,6 +105,7 @@ test_entry:
         jsr diag_init
         lda #$00                   ; ERR files only; keep the screen quiet
         sta diag_screen
+        sta em_on                  ; captured-print proof: no statement emitter
         jsr parse_file
         jsr diag_finish
         sta diag_count

newLang/tests/regression/harness.tests.ps1

@@ -66,9 +66,11 @@ exit 0
 '@, [Text.UTF8Encoding]::new($false))
 
 function Invoke-Harness([string[]]$Extra) {
-    $arguments = @("-NoProfile", "-ExecutionPolicy", "Bypass", "-File", ('"' + $harness + '"'),
-        "-Manifest", ('"' + $manifest + '"'), "-BuildRoot", ('"' + $buildRoot + '"'),
-        "-Baseline", ('"' + $baseline + '"'), "-Results", ('"' + $results + '"')) + $Extra
+    # The call operator quotes arguments that contain spaces itself. Embedding
+    # quotes here breaks PowerShell 7.3+, which escapes them into the path.
+    $arguments = @("-NoProfile", "-ExecutionPolicy", "Bypass", "-File", $harness,
+        "-Manifest", $manifest, "-BuildRoot", $buildRoot,
+        "-Baseline", $baseline, "-Results", $results) + $Extra
     $output = & (Get-Command powershell).Source @arguments 2>&1 | Out-String
     return @{ Output = $output; Code = $LASTEXITCODE }
 }