{now} is the start of the run, as the spec always said

The clock was read once per directory, so a run of several directories
stamped several different times - and a review that took a few seconds
could put one run's files into two folders, or at midnight two dates.
The spec (§7.3) says "the start of the run"; krino.conf(5) documented
the behaviour rather than the intent, so the two contradicted each
other.

The session now carries the run's clock and every directory plans with
it. Engine.Plan keeps its meaning for a caller with no session of its
own; Session.Plan passes the run's own start.

1 files changed, 9 insertions, 3 deletions

diff --git a/internal/engine/session.go b/internal/engine/session.go
index 8d5977a..09cf246 100644
--- a/internal/engine/session.go
+++ b/internal/engine/session.go
@@ -5,6 +5,7 @@ package engine
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"git.labunix.xyz/krino/internal/journal"
 	"git.labunix.xyz/krino/internal/lock"
@@ -27,6 +28,10 @@ type Session struct {
 	claims *plan.Claims
 	landed []string // where this run's applied files ended up, in order
 	dry    bool
+
+	// started is the run's own clock: what {now:FMT} means for every
+	// directory of this run, fixed when the session begins.
+	started time.Time
 }
 
 // NewSession starts a run. The log is opened by OpenLog, or by the first
@@ -35,7 +40,7 @@ type Session struct {
 // create a log a dry run would not. The caller closes the session when the
 // run is over.
 func (e *Engine) NewSession(dry bool) (*Session, error) {
-	return &Session{e: e, claims: plan.NewClaims(), dry: dry}, nil
+	return &Session{e: e, claims: plan.NewClaims(), dry: dry, started: e.Now()}, nil
 }
 
 // OpenLog opens the log and takes the run id, once. A dry session does
@@ -86,9 +91,10 @@ func (s *Session) LockDirs(ctx context.Context, names []string, wait bool) ([]*l
 	return held, nil
 }
 
-// Plan builds d's plan with the run's claims.
+// Plan builds d's plan with the run's claims, and the run's clock: every
+// directory of one run stamps {now:FMT} with the same moment.
 func (s *Session) Plan(ctx context.Context, d *Dir) (*DirPlan, error) {
-	return s.e.Plan(ctx, d, s.claims)
+	return s.e.PlanAt(ctx, d, s.claims, s.started)
 }
 
 // Apply carries out the approved files of dp and logs the run's steps,