Does an employee's eagerness to inform his employer of his work results and diligence in it, in order to improve his professional standing, without harming others or pleasing his superior in a way that angers Allah, count as minor shirk (associating partners with Allah) or as taking means to increase one's provision, alongside supplication and seeking from Allah?

The forbidden ostentation (riya') is seeking status in the hearts of people through acts of worship. As for seeking prestige and status through means other than acts of worship, it is not inherently blameworthy. It may be praiseworthy or blameworthy depending on the intention. Just as seeking wealth is not inherently blameworthy, so too is seeking prestige. Therefore, seeking prestige, if it is not through acts of worship, is like seeking wealth; it can be permissible, an act of obedience, or blameworthy, depending on its purpose. Accordingly, a truthful employee informing their manager about their work to improve their salary, provided their work is legitimate, is permissible and does not fall under the forbidden ostentation.