Promote Xevious (U) and Zanac (U) from _wip/ to NROM/

- Xevious (U): Promoted from _wip/NROM/Xevious (U)/ to NROM/Xevious (U)/
  - Pass 3 complete: 34.5% code coverage, 143 semantic entry points,
    4 named data tables, ~20 semantic ZP aliases
  - NROM mapper 0, 32 KB PRG, 8 KB CHR, horizontal mirroring

- Zanac (U): Promoted from _wip/UNROM/Zanac (U)/ to NROM/Zanac (U)/
  - Pass 3 complete: 34.5% code coverage (bank 7 only), 133 semantic
    entry points, 26 named data tables, 14 semantic ZP aliases
  - UNROM mapper 2, 128 KB PRG (8 banks), no CHR
  - Bank 7 fixed at CPU -; banks 0-6 switchable at 000-
  - Bank 7 assembled separately as prg.07.s with .org

Both projects build byte-identical. Updated root README.md inventory,
per-project details, and WIP.md accordingly.

Move Zanac (U) to UNROM/ mapper directory

Zanac (U) is a UNROM (mapper 2) game, not NROM (mapper 0). Move it to
the correct mapper directory and update README.md and WIP.md references
accordingly. Update project counts in WIP.md (857->856 total, UNROM
98->97 projects).

Promote Mermaids of Atlantis (U) from _wip/ to MAPPER8/

Additional cleanup of Mermaids of Atlantis

MAPPER8/Mermaids of Atlantis (U)/locals.inc

@@ -0,0 +1,37 @@
+; Zero-page aliases for this project.
+; Pass 1+ adds proven semantic names here;
+; addresses whose role is not yet determined keep the neutral ZpXX
+; form.
+
+Zp00    = $00
+Zp01    = $01
+Zp02    = $02
+Zp2F    = $2F
+Zp6A    = $6A
+
+; ---------------------------------------------------------------------------
+; Semantic zero-page aliases (Pass 3)
+;
+; Every alias below was read out of this dump's own code.  An address whose
+; role is the same at every reference is renamed everywhere; an address that
+; is reused for several roles keeps the neutral ZpXX name outside the
+; routines where the role is proven, and the per-site choice is recorded in
+; sites.tsv.
+; ---------------------------------------------------------------------------
+
+TempVar0        = $00 ; semantic alias for Zp00 (general-purpose zero-page temp, used at $804D,$8057,$806B)
+TempVar1        = $01 ; semantic alias for Zp01 (general-purpose zero-page temp, used at $804F,$8062,$8066,$806D,$807D)
+TempVar2        = $02 ; semantic alias for Zp02 (general-purpose zero-page temp, used at $8076)
+LoopCounter     = $2F ; semantic alias for Zp2F (incremented at $8083, likely frame/loop counter)
+StatusByte      = $6A ; semantic alias for Zp6A (stored at $8081, likely status/flags register)
+
+; Clean marker section placeholder - will be filled by tools if needed
+; ---------------------------------------------------------------------------
+; Semantic zero-page aliases (Pass 3)
+;
+; Every alias below was read out of this dump's own code.  An address whose
+; role is the same at every reference is renamed everywhere; an address that
+; is reused for several roles keeps the neutral ZpXX name outside the
+; routines where the role is proven, and the per-site choice is recorded in
+; sites.tsv.
+; ---------------------------------------------------------------------------