feat: import agents_and_robots platform as unibots (Matrix-out, unibus transport)

Reemplaza el scaffold del echobot por la plataforma completa de bots traida
desde ~/DataProyects/Github/agents_and_robots tras la operacion Matrix-out:
los bots ya no hablan por Matrix sino por el bus unibus (modelo todo-rooms +
E2E via shell/transportunibus sobre github.com/enmanuel/unibus/pkg/client).

- go.mod: replace de unibus -> ../unibus y de fn-registry -> ../../../.. (paths
  relativos reajustados a la nueva ubicacion dentro de fn_registry).
- app.md: bump a 0.2.0, descripcion + arquitectura + comandos + gotchas reales.
- modulo Go conservado como github.com/enmanuel/agents (sin reescribir imports).

agents_and_robots queda archivado como museo de la era Matrix.

pkg/decision/engine.go

@@ -0,0 +1,76 @@
+package decision
+
+import (
+	"strings"
+)
+
+// Rule maps a condition to a set of actions.
+type Rule struct {
+	Name    string
+	Match   MatchFunc
+	Actions []Action
+}
+
+// MatchFunc is a pure predicate over a MessageContext.
+type MatchFunc func(ctx MessageContext) bool
+
+// Evaluate runs all rules against the context and returns the matching actions. Pure.
+func Evaluate(ctx MessageContext, rules []Rule) []Action {
+	var actions []Action
+	for _, rule := range rules {
+		if rule.Match(ctx) {
+			actions = append(actions, rule.Actions...)
+		}
+	}
+	return actions
+}
+
+// MatchCommand returns a MatchFunc that matches when the command equals cmd.
+func MatchCommand(cmd string) MatchFunc {
+	return func(ctx MessageContext) bool {
+		return strings.EqualFold(ctx.Command, cmd)
+	}
+}
+
+// MatchPrefix returns a MatchFunc that matches when content starts with prefix.
+func MatchPrefix(prefix string) MatchFunc {
+	return func(ctx MessageContext) bool {
+		return strings.HasPrefix(ctx.Content, prefix)
+	}
+}
+
+// MatchAny returns a MatchFunc that matches any message.
+func MatchAny() MatchFunc {
+	return func(_ MessageContext) bool { return true }
+}
+
+// MatchMinPowerLevel returns a MatchFunc that requires a minimum Matrix power level.
+func MatchMinPowerLevel(level int) MatchFunc {
+	return func(ctx MessageContext) bool {
+		return ctx.PowerLevel >= level
+	}
+}
+
+// And composes multiple MatchFuncs with logical AND.
+func And(fns ...MatchFunc) MatchFunc {
+	return func(ctx MessageContext) bool {
+		for _, fn := range fns {
+			if !fn(ctx) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+// Or composes multiple MatchFuncs with logical OR.
+func Or(fns ...MatchFunc) MatchFunc {
+	return func(ctx MessageContext) bool {
+		for _, fn := range fns {
+			if fn(ctx) {
+				return true
+			}
+		}
+		return false
+	}
+}