1.0: Fix search, doctor, api, report and logs #1330

Goal: search, doctor, api, report and logs give truthful results, documented exit codes and terminal-safe output.

• major: search --author filters only the first page. src/cmd/search.rs:464-526.
• major: Bobbin errors lose their source, so unreachable exits 1. src/clients/tangled/bobbin/mod.rs:171-177.
• major: api mints the knot audience for setDefaultBranch. src/cmd/api.rs:363-380.
• major: logs --json --follow writes notices to stdout. src/cmd/logs/render.rs:1464-1530.
• major: Log rows and the report board name print control characters. src/cmd/logs/*, src/cmd/report.rs:236-239.
• minor: hit() never returns None. src/cmd/search.rs:298-347, 479-505.
• minor: At --limit 1000, search says to raise the limit. src/cmd/search.rs:604-613.
• minor: Comment hits have repo_did null. src/cmd/search.rs:152-158, 326-329.
• minor: doctor says scopes ok without a session. src/cmd/doctor.rs:674-690.
• minor: doctor --json is rejected. src/cmd/doctor.rs:208, src/main.rs:256-264.
• minor: logs -n 0 says nothing matched. src/cmd/logs/render.rs:1171.
• minor: logs git panics on a non-ASCII sha. src/cmd/logs/git.rs:241.
• minor: api gives -f repo= advice to --input callers. src/cmd/api.rs:405.
• minor: report --title '' is accepted. src/cmd/report.rs:163.
• minor: report exits 1 for a bad --space. src/cmd/report.rs:188-194.
• minor: warning! and debug output keep control characters. src/term/say.rs:324-346, src/logging/debug.rs:28-33.