feat(asapquery): execute planned PromQL with conformant fallback

[zzylol]

Stacked on #497.

Implements Phase E of the ASAPQuery compatibility profile:

• compiles exact sum, increase, and rate materializations into explicit QueryPlan ExactReadout nodes
• executes rate/increase from reset-aware counter state with boundary extrapolation
• evaluates range queries at exact Prometheus start+n*step timestamps
• honors explicit instant evaluation time
• preserves timeout, authorization, and tenant context on instant/range Prometheus fallback
• keeps old counter binary state readable and adds a detectable reset-aware wire extension
• fixes keyed counter serialization, merge, and query semantics

Validation:

• cargo test -p control_plane --lib (633 passed)
• cargo test -p data_plane --lib (964 passed before one compatibility adjustment; the sole failure was fixed and rerun successfully)
• targeted exact compiler, counter reset/rate, range-step, fallback context, and legacy serialization tests pass.

Do not merge before the lower stack lands.

[zzylol]

Stack continuation: #499 adds the executable collector-free compatibility E2E/demo and fixes runtime defects found by that conformance suite.