This paper develops a unified geometric framework in which observable temporal and spatial structure emerge from tensorial projections of an invariant scalar evolution parameter. The framework integrates scalar-clock evolution, quaternionic selector geometry, and operational time measurement into a single hierarchical structure summarized as: Scalar → Tensor → Observable. An invariant scalar clock parameter φ defines monotonic physical evolution independent of coordinate time or proper time. Observable temporal structure arises through tensorial projection determined by an awareness tensor field, which maps scalar evolution into directional spacetime structure while preserving the causal geometry of relativistic spacetime. Quaternionic selector geometry provides a natural representation of the directional degrees of freedom generated by tensorial projection. Localized physical systems are represented by quaternionic primitives q(φ)=R(φ)u(φ), where the invariant magnitude R(φ) determines expansion scale and the unit quaternion u(φ)∈S³≃SU(2) determines selector orientation. Observable quantities depend on relations between selector configurations along scalar evolution. Operational time measurement is interpreted as a tensorially projected readout of scalar evolution, with measurable time increments satisfying dτ̂ = Ξ dφ for system-dependent response functions Ξ. This provides a unified interpretation of proper time, clock measurements, and dynamical progress across physical systems. Interference phenomena, including recent temporal double-slit experiments, arise naturally within the framework as overlap relations between selector configurations at distinct scalar times. Observable structure, therefore, depends on relations along scalar evolution rather than on spatial geometry alone. The resulting framework provides a coherent synthesis of previous Trinity Geometric Model results and establishes a unified geometric interpretation linking scalar-clock evolution, tensorial projection, quaternionic selector geometry, and operational measurement. Temporal and spatial observables emerge as complementary tensorial projections of a single invariant scalar geometric evolution. This work extends the Trinity framework into a covariant scalar–tensor field theory by introducing a dynamical awareness tensor sourced by a record current constructed from quaternionic overlap invariants. A weak-field analysis shows that deviations of the awareness field scale with local coherence density, leading to small corrections to operational time. In principle, high-precision atomic clocks operating in strongly entangled environments may exhibit minute, information-dependent deviations from standard relativistic predictions, while the theory reduces to General Relativity in the absence of record formation. Revised version with full covariant dynamics, Born-rule derivation, and clarified parameter interpretation. This version adds an explicit mathematical formulation of the Scalar–Tensor–Observable hierarchy, develops the SU(2) selector geometry and its Hopf structure, introduces a covariant record-current source for the awareness field, and explores empirical implications including clock-rate deviations and a geometric interpretation of vacuum energy and Casimir-type boundary effects. This version introduces a formal interpretation of symmetry breaking within the Scalar–Tensor–Observable (STO) hierarchy as a continuous tensorial projection process. A new subsection establishes the connection to Noether’s theorem and spontaneous symmetry breaking, showing that observable anisotropy arises from a dynamically evolving tensorial order parameter rather than a fixed vacuum state. A schematic figure is added to clarify the symmetry-to-observable mapping. This version added a new section cluster extending the Scalar–Tensor–Observable framework from operational time and projected observables into persistent record formation, quantum rotational quantization, and spin closure structure. The update introduces a distinction-to-record pathway mediated by the awareness tensor, interprets angular momentum quantization as thresholded rotational record formation, and develops a closure-class account of half-integer spin in which electron spin-12\tfrac1221 is treated as a doubled-closure tensorial record. The revision also proposes a structural interpretation of Pauli exclusion as an occupancy constraint associated with doubled-closure fermionic states. This version clarifies periodic phenomena as recurrent tensor-clock coupling and extends the STO observable hierarchy by distinguishing local curvature records from global holonomy records. These additions connect scalar-clock operational time to waves, pulses, detector records, and the later Trinity gauge/holonomy developments.