# V3 step 5.6 — module-qualified symbols + real qualified access (done 2026-09-22)

Removes both separate-compilation limitations from step 5.4/5.5.
Suite 97/97 (54 run — incl. 4 trap-aborts, 7 sessions, 3
session-output, 2 session-input, 1 unit — + 43 reject).
LL(1)-clean, zero gm2 warnings.

## 1. Module-qualified globals

Module-level `VAR`/`CONST` data now emits as `$<mod>_<name>`
(previously `$<name>`), so two modules with a global of the same
name no longer collide at link time. `QbeGen.SetModule` (called by
each unit's `Begin*`) supplies the module; `DeclVar`/`DeclConst`
prefix it. Real-const startup flushes and the `ExitCode` load use
the same qualified name.

## 2. Real per-module qualified access

`L.x` / `L.P` no longer flatten-clone under the plain name (which
let one library's export shadow another's). New
`SymTab.MaterializeAlias(mod, name, alias)` clones under a
per-module key `<mod>$<name>` (`$` can't appear in identifiers), and
the symbol node keeps:
- `sym` — the base symbol name (for QBE mangling/global names), and
- `mod` — the defining module.

`SymBase` and `GlobalRef` read those back; `QbeGen.Mangled` now
mangles via `SymBase` (drops any alias prefix) and `SymRef` builds
`$<mod>_<sym>` for data access. All other lookups
(type/kind/uid/params/result/external/depth) work unchanged because
they only need `Find(alias)`.

## Tests

- `ClashProg` → 60: two modules `ClashA`/`ClashB` each with a global
  `count` **and** a procedure `Get`; the program uses both
  qualified. Image shows `$ClashA_count`/`$ClashB_count` and
  `Get_0`/`Get_1`.
- `MixProg` → prints `7`: `TextIO.WriteInt` (console) and
  `Files.WriteInt` (file) in one program — the exact case that
  failed before this pass.
- Full prior suite unchanged (95 → 97).

## Remaining known edge

`FROM A IMPORT x` followed by `FROM B IMPORT x` is still
first-wins (`Materialize` returns the existing node) — genuinely
ambiguous by name; callers should use qualified access or distinct
names. Qualified access is fully per-module.

## Unblocks

`Storage`/`SYSTEM` (`ADDRESS`, generic pointers) and the step-7
syslib port: `SYSTEM`/`Storage`/`Trap` can now be ordinary modules
whose internals bind externals without symbol collisions.