Numbers, handles, text, and tabular sections

Part of the workspace execution and envelope protocol of the ruststa command.

PROTO-REQ-0100 Numbers in JSON envelopes use canon_f64 (converting -0.0 to +0.0 and emitting shortest round-trip IEEE 754 f64 decimals for _ns, _pf, and _s fields, and 0.1 rounded decimals for cell_delay_pct and wire_delay_pct). In --format text mode, nanoseconds and picofarads are formatted to 4 decimals (0.0000 for -0.0), or full round-trip precision when --exact is passed; missing values render as — in text and null in JSON.

PROTO-REQ-0110 Every rusteda.v1 envelope on a timed revision includes the three standard header objects in fixed key order: - scope: corner, wire_model, parasitics, drc_status, wire_load, delay_calculator, clock_model, cppr, backend, precision (plus corners when multi-corner); - completeness: constrained_endpoints, unconstrained_endpoints, clock_domains, unconstrained_by_reason, unconstrained_inputs, disabled_arcs, unanalyzed_arcs; - metrics: wns_ns, tns_ns, violating_endpoints, whs_ns, ths_ns, hold_violating_endpoints, worst_setup_slack_ns, worst_hold_slack_ns.

PROTO-REQ-0120 Every object handle emitted by ruststa matches [A-Za-z0-9_-]+ without underscores between prefix and number: path<N> (1-based rank over setup checks then hold checks), inst<N>, net<N>, pin<N>, and port<N> (1 + canonical row in NETLIST v1), mm<N> (1-based mismatch rank in ruststa check), and sel<N> (selection entry from ui_state.json).

PROTO-REQ-0130 ruststa report provides eight tabular section models from sta.rbin: summary, paths, endpoints, pins, clocks, checks, unconstrained, and notes. Each section object in JSON contains {columns, total, matched, shown, rows}.

PROTO-REQ-0131 Filter expressions (ruststa report --filter <EXPR>): supports setup<N, hold<N, slack<N, violating, clock=<NAME>, kind=setup|hold, and substring matching endpoint~<SUBSTR>, pin~<SUBSTR>, or name~<SUBSTR>. Malformed filter expressions are rejected with USAGE (error[A0003], exit 1).

PROTO-REQ-0132 Sorting (ruststa report --sort <KEY> [--reverse]) uses f64::total_cmp for numeric keys (slack, setup, hold, arrival, required, cap, slew, period, fanout, rank) with deterministic tie-breaking by object name or index so row order never depends on --threads. Unknown sort keys are rejected with USAGE (error[A0003], exit 1).