Constant CROSSTRACK_DDL 

pub const CROSSTRACK_DDL: &str = "
CREATE TABLE IF NOT EXISTS disassembly (
    id              INTEGER PRIMARY KEY,
    session_id      TEXT NOT NULL REFERENCES sessions(id),
    symbol_id       INTEGER REFERENCES symbols(id),
    source          TEXT NOT NULL,
    tier            TEXT,
    code_bytes      INTEGER,
    asm_text        TEXT NOT NULL,
    asm_lines_json  TEXT,
    collected_at    TEXT NOT NULL,
    trigger         TEXT,
    layer_id        INTEGER REFERENCES layers(id)
);
CREATE INDEX IF NOT EXISTS idx_disasm_sym ON disassembly(symbol_id);

CREATE TABLE IF NOT EXISTS source_snapshots (
    id              INTEGER PRIMARY KEY,
    session_id      TEXT NOT NULL REFERENCES sessions(id),
    symbol_id       INTEGER REFERENCES symbols(id),
    file            TEXT,
    line_start      INTEGER,
    line_end        INTEGER,
    text            TEXT,
    content_hash    TEXT,
    collected_at    TEXT NOT NULL
);
CREATE INDEX IF NOT EXISTS idx_src_sym ON source_snapshots(symbol_id);

CREATE TABLE IF NOT EXISTS alloc_sites (
    id              INTEGER PRIMARY KEY,
    session_id      TEXT NOT NULL REFERENCES sessions(id),
    symbol_id       INTEGER REFERENCES symbols(id),
    bytes_total     INTEGER,
    count           INTEGER,
    largest_bytes   INTEGER,
    collected_at    TEXT NOT NULL,
    layer_id        INTEGER REFERENCES layers(id)
);
CREATE INDEX IF NOT EXISTS idx_alloc_site_sym ON alloc_sites(symbol_id);
";

Cross-track shared tables — joinable from either debug or profile tracks via symbol_id. Populated by on-demand collectors.